diff --git a/source/ChanSort.Loader.M3u/ChanSort.Loader.M3u.csproj b/source/ChanSort.Loader.M3u/ChanSort.Loader.M3u.csproj
new file mode 100644
index 0000000..1b0b711
--- /dev/null
+++ b/source/ChanSort.Loader.M3u/ChanSort.Loader.M3u.csproj
@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{484028B6-3AAE-4F7E-A88A-76BEEB70203B}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>ChanSort.Loader.M3u</RootNamespace>
+    <AssemblyName>ChanSort.Loader.M3u</AssemblyName>
+    <TargetFrameworkVersion>v4.6</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x86\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <LangVersion>latest</LangVersion>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
+    <OutputPath>bin\x86\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <Optimize>true</Optimize>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <LangVersion>latest</LangVersion>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Web" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Channel.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Serializer.cs" />
+    <Compile Include="SerializerPlugin.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ChanSort.Api\ChanSort.Api.csproj">
+      <Project>{dccffa08-472b-4d17-bb90-8f513fc01392}</Project>
+      <Name>ChanSort.Api</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>
\ No newline at end of file
diff --git a/source/ChanSort.Loader.M3u/Channel.cs b/source/ChanSort.Loader.M3u/Channel.cs
new file mode 100644
index 0000000..a309f69
--- /dev/null
+++ b/source/ChanSort.Loader.M3u/Channel.cs
@@ -0,0 +1,14 @@
+using ChanSort.Api;
+
+namespace ChanSort.Loader.M3u
+{
+   internal class Channel : ChannelInfo
+   {
+     public string Uri { get; }
+
+     public Channel(int index, int progNr, string name, string uri) : base(SignalSource.IP, index, progNr, name)
+     {
+       this.Uri = uri;
+     }
+   }
+}
diff --git a/source/ChanSort.Loader.M3u/Properties/AssemblyInfo.cs b/source/ChanSort.Loader.M3u/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..d800aaa
--- /dev/null
+++ b/source/ChanSort.Loader.M3u/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ChanSort.Loader.M3u")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ChanSort.Loader.M3u")]
+[assembly: AssemblyCopyright("Copyright ©  2020")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("484028b6-3aae-4f7e-a88a-76beeb70203b")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/source/ChanSort.Loader.M3u/Serializer.cs b/source/ChanSort.Loader.M3u/Serializer.cs
new file mode 100644
index 0000000..002946f
--- /dev/null
+++ b/source/ChanSort.Loader.M3u/Serializer.cs
@@ -0,0 +1,161 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Web;
+using ChanSort.Api;
+
+namespace ChanSort.Loader.M3u
+{
+  class Serializer : SerializerBase
+  {
+    private readonly ChannelList allChannels = new ChannelList(SignalSource.IP, "All");
+
+    private List<string> lines = new List<string>();
+
+    #region ctor()
+    public Serializer(string inputFile) : base(inputFile)
+    {
+      this.Features.ChannelNameEdit = ChannelNameEditMode.All;
+      this.Features.DeleteMode = DeleteMode.Physically;
+      this.Features.SortedFavorites = false;
+      this.Features.SupportedFavorites = 0;
+      this.Features.CanLockChannels = false;
+      this.Features.CanSkipChannels = false;
+      this.Features.CanHideChannels = false;
+
+      this.DataRoot.AddChannelList(this.allChannels);
+
+      base.DefaultEncoding = new UTF8Encoding(false);
+      this.allChannels.VisibleColumnFieldNames = new List<string>()
+      {
+        "OldPosition", "Position", "Name", "FreqInMhz", "Polarity", "SymbolRate", "VideoPid", "AudioPid", "Satellite"
+      };
+    }
+    #endregion
+
+    #region Load()
+    public override void Load()
+    {
+      var rdr = new StreamReader(this.FileName);
+      var header = rdr.ReadLine()?.TrimEnd();
+      if (header != "#EXTM3U")
+        throw new FileLoadException("Unsupported .m3u file: " + this.FileName);
+
+      int lineNr=0;
+      string line1, line2;
+      while ((line1 = rdr.ReadLine()) != null)
+      {
+        ++lineNr;
+        if (line1.Trim() == "") 
+          continue;
+
+        var lineNr1 = lineNr;
+        while ((line2 = rdr.ReadLine()) != null)
+        {
+          ++lineNr;
+          if (line2.Trim() != "")
+          {
+            ReadChannel(lineNr1, line1, line2);
+            break;
+          }
+        }
+      }
+    }
+    #endregion
+
+    #region ReadChannel()
+    private static readonly Regex ExtInfRegex = new Regex(@"^#EXTINF:\d+,(?:(\d+)\. )?(.*)$");
+    private void ReadChannel(int lineNr, string line1, string line2)
+    {
+      var match = ExtInfRegex.Match(line1);
+      if (!match.Success)
+        throw new FileLoadException($"Unsupported #EXTINF line #{lineNr}: {line1}");
+
+      int progNr = string.IsNullOrEmpty(match.Groups[2].Value)
+        ? this.allChannels.Count + 1
+        : this.ParseInt(match.Groups[1].Value);
+
+      Uri uri;
+      try
+      {
+        uri = new Uri(line2);
+      }
+      catch
+      {
+         throw new FileLoadException($"Unsupported URI in line #{lineNr}: {line2}");
+      }
+
+      var chan = new Channel(lineNr, progNr, match.Groups[2].Value, line2);
+      chan.Satellite = uri.GetLeftPart(UriPartial.Path);
+      var parms = HttpUtility.ParseQueryString(uri.Query);
+      foreach (var key in parms.AllKeys)
+      {
+        var val = parms.Get(key);
+        switch (key)
+        {
+          case "freq":
+            chan.FreqInMhz = this.ParseInt(val);
+            break;
+          case "pol":
+            if (val.Length == 1)
+              chan.Polarity = Char.ToUpper(val[0]);
+            break;
+          case "sr":
+            chan.SymbolRate = this.ParseInt(val);
+            break;
+          case "pids":
+            var pids = val.Split(',');
+            //if (pids.Length > 3)
+            //  chan.PcrPid = this.ParseInt(pids[3]);
+            if (pids.Length > 4)
+              chan.VideoPid = this.ParseInt(pids[4]);
+            if (pids.Length > 5)
+              chan.AudioPid = this.ParseInt(pids[5]);
+            break;
+        }
+      }
+
+      this.DataRoot.AddChannel(this.allChannels, chan);
+    }
+    #endregion
+
+    #region DefaultEncoding
+    public override Encoding DefaultEncoding
+    {
+      get => base.DefaultEncoding; // set to UTF-8 without BOM in constructor
+      set { } // can't be changed
+    }
+    #endregion
+
+
+    #region Save()
+    public override void Save(string tvOutputFile)
+    {
+      using var file = new StreamWriter(new FileStream(tvOutputFile, FileMode.Create), this.DefaultEncoding);
+      file.WriteLine("#EXTM3U");
+      foreach (ChannelInfo channel in this.allChannels.GetChannelsByNewOrder())
+      {
+        // when a reference list was applied, the list may contain proxy entries for deleted channels, which must be ignored
+        if (channel is Channel chan && !channel.IsDeleted)
+        {
+          file.WriteLine($"#EXTINF:0,{chan.NewProgramNr}. {chan.Name}");
+          file.WriteLine(chan.Uri);
+        }
+      }
+
+      this.FileName = tvOutputFile;
+    }
+    #endregion
+
+    #region GetFileInformation()
+    public override string GetFileInformation()
+    {
+      StringBuilder sb = new StringBuilder();
+      sb.Append(base.GetFileInformation());
+      return sb.ToString();
+    }
+    #endregion
+  }
+}
diff --git a/source/ChanSort.Loader.M3u/SerializerPlugin.cs b/source/ChanSort.Loader.M3u/SerializerPlugin.cs
new file mode 100644
index 0000000..1ba18ea
--- /dev/null
+++ b/source/ChanSort.Loader.M3u/SerializerPlugin.cs
@@ -0,0 +1,16 @@
+using ChanSort.Api;
+
+namespace ChanSort.Loader.M3u
+{
+  public class SerializerPlugin : ISerializerPlugin
+  {
+    public string DllName { get; set; }
+    public string PluginName => "m3u (WinAmp, VLC, SAT>IP, ...)";
+    public string FileFilter => "*.m3u";
+    
+    public SerializerBase CreateSerializer(string inputFile)
+    {
+      return new Serializer(inputFile);
+    }
+  }
+}
diff --git a/source/ChanSort.sln b/source/ChanSort.sln
index 046f91e..005d6ee 100644
--- a/source/ChanSort.sln
+++ b/source/ChanSort.sln
@@ -74,6 +74,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Test.Loader.Toshiba", "Test
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Test.Loader.VDR", "Test.Loader.VDR\Test.Loader.VDR.csproj", "{AED060F0-495C-494C-89C2-7A96A0FA3762}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ChanSort.Loader.M3u", "ChanSort.Loader.M3u\ChanSort.Loader.M3u.csproj", "{484028B6-3AAE-4F7E-A88A-76BEEB70203B}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -408,6 +410,18 @@ Global
 		{AED060F0-495C-494C-89C2-7A96A0FA3762}.Release|Mixed Platforms.Build.0 = Release|Any CPU
 		{AED060F0-495C-494C-89C2-7A96A0FA3762}.Release|x86.ActiveCfg = Release|x86
 		{AED060F0-495C-494C-89C2-7A96A0FA3762}.Release|x86.Build.0 = Release|x86
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|x86.ActiveCfg = Debug|x86
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Debug|x86.Build.0 = Debug|x86
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|Mixed Platforms.Build.0 = Release|Any CPU
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|x86.ActiveCfg = Release|x86
+		{484028B6-3AAE-4F7E-A88A-76BEEB70203B}.Release|x86.Build.0 = Release|x86
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/source/ChanSort/ChanSort.csproj b/source/ChanSort/ChanSort.csproj
index 1446333..45bf3ce 100644
--- a/source/ChanSort/ChanSort.csproj
+++ b/source/ChanSort/ChanSort.csproj
@@ -404,6 +404,10 @@
       <Project>{e972d8a1-2f5f-421c-ac91-cff45e5191be}</Project>
       <Name>ChanSort.Loader.LG</Name>
     </ProjectReference>
+    <ProjectReference Include="..\ChanSort.Loader.M3u\ChanSort.Loader.M3u.csproj">
+      <Project>{484028b6-3aae-4f7e-a88a-76beeb70203b}</Project>
+      <Name>ChanSort.Loader.M3u</Name>
+    </ProjectReference>
     <ProjectReference Include="..\ChanSort.Loader.Panasonic\ChanSort.Loader.Panasonic.csproj">
       <Project>{68da8072-3a29-4076-9f64-d66f38349585}</Project>
       <Name>ChanSort.Loader.Panasonic</Name>
diff --git a/source/ChanSort/MainForm.cs b/source/ChanSort/MainForm.cs
index 93ca1f3..198bfce 100644
--- a/source/ChanSort/MainForm.cs
+++ b/source/ChanSort/MainForm.cs
@@ -1512,7 +1512,7 @@ namespace ChanSort.Ui
       if (col == this.colDebug) return col.Visible;
       if (col == this.colSignalSource) return col.Visible;
       if (col == this.colLogicalIndex) return col.Visible;
-      if (col == this.colPolarity) return (source & SignalSource.Sat) != 0;
+      if (col == this.colPolarity) return (source & SignalSource.Sat) != 0 || (source & SignalSource.IP) != 0;
 
       return true;
     }
@@ -1618,7 +1618,7 @@ namespace ChanSort.Ui
       this.btnToggleFavF.Enabled = mayEdit && (this.DataRoot.SupportedFavorites & Favorites.F) != 0 && this.subListIndex != 6;
       this.btnToggleFavG.Enabled = mayEdit && (this.DataRoot.SupportedFavorites & Favorites.G) != 0 && this.subListIndex != 7;
       this.btnToggleFavH.Enabled = mayEdit && (this.DataRoot.SupportedFavorites & Favorites.H) != 0 && this.subListIndex != 8;
-      this.btnToggleLock.Enabled = mayEdit;
+      this.btnToggleLock.Enabled = mayEdit && this.DataRoot.CanLock;
 
       if (afterFileLoad)
       {
diff --git a/source/ChanSort/MainForm.resx b/source/ChanSort/MainForm.resx
index 0f7a8ae..c76ca5c 100644
--- a/source/ChanSort/MainForm.resx
+++ b/source/ChanSort/MainForm.resx
@@ -270,7 +270,7 @@
     <value>Numeric</value>
   </data>
   <data name="gridLeft.Size" type="System.Drawing.Size, System.Drawing">
-    <value>499, 374</value>
+    <value>499, 368</value>
   </data>
   <data name="gridLeft.TabIndex" type="System.Int32, mscorlib">
     <value>1</value>
@@ -291,7 +291,7 @@
     <value>Bottom</value>
   </data>
   <data name="lblHotkeyLeft.Location" type="System.Drawing.Point, System.Drawing">
-    <value>2, 428</value>
+    <value>2, 422</value>
   </data>
   <data name="lblHotkeyLeft.Padding" type="System.Windows.Forms.Padding, System.Windows.Forms">
     <value>2, 2, 2, 2</value>
@@ -330,7 +330,7 @@
     <value>6, 13</value>
   </data>
   <data name="$this.ClientSize" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 557</value>
+    <value>1402, 551</value>
   </data>
   <data name="tabSubList.Anchor" type="System.Windows.Forms.AnchorStyles, System.Windows.Forms">
     <value>Bottom, Left, Right</value>
@@ -339,7 +339,7 @@
     <value>0, 5</value>
   </data>
   <data name="pageProgNr.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1405, 0</value>
+    <value>1391, 0</value>
   </data>
   <data name="pageProgNr.Text" xml:space="preserve">
     <value>Pr#</value>
@@ -357,7 +357,7 @@
     <value>0</value>
   </data>
   <data name="tabSubList.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1411, 22</value>
+    <value>1397, 22</value>
   </data>
   <data name="tabSubList.TabIndex" type="System.Int32, mscorlib">
     <value>6</value>
@@ -381,7 +381,7 @@
     <value>0, 83</value>
   </data>
   <data name="grpSubList.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 27</value>
+    <value>1402, 27</value>
   </data>
   <data name="grpSubList.TabIndex" type="System.Int32, mscorlib">
     <value>10</value>
@@ -795,7 +795,7 @@
     <value>0, 0</value>
   </data>
   <data name="barDockControlTop.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 26</value>
+    <value>1402, 26</value>
   </data>
   <data name="&gt;&gt;barDockControlTop.Name" xml:space="preserve">
     <value>barDockControlTop</value>
@@ -813,10 +813,10 @@
     <value>Bottom</value>
   </data>
   <data name="barDockControlBottom.Location" type="System.Drawing.Point, System.Drawing">
-    <value>0, 557</value>
+    <value>0, 551</value>
   </data>
   <data name="barDockControlBottom.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 0</value>
+    <value>1402, 0</value>
   </data>
   <data name="&gt;&gt;barDockControlBottom.Name" xml:space="preserve">
     <value>barDockControlBottom</value>
@@ -837,7 +837,7 @@
     <value>0, 26</value>
   </data>
   <data name="barDockControlLeft.Size" type="System.Drawing.Size, System.Drawing">
-    <value>0, 531</value>
+    <value>0, 525</value>
   </data>
   <data name="&gt;&gt;barDockControlLeft.Name" xml:space="preserve">
     <value>barDockControlLeft</value>
@@ -855,10 +855,10 @@
     <value>Right</value>
   </data>
   <data name="barDockControlRight.Location" type="System.Drawing.Point, System.Drawing">
-    <value>1416, 26</value>
+    <value>1402, 26</value>
   </data>
   <data name="barDockControlRight.Size" type="System.Drawing.Size, System.Drawing">
-    <value>0, 531</value>
+    <value>0, 525</value>
   </data>
   <data name="&gt;&gt;barDockControlRight.Name" xml:space="preserve">
     <value>barDockControlRight</value>
@@ -1018,7 +1018,7 @@
     <value>Top, Right</value>
   </data>
   <data name="picDonate.Location" type="System.Drawing.Point, System.Drawing">
-    <value>1238, 4</value>
+    <value>1224, 4</value>
   </data>
   <data name="picDonate.Size" type="System.Drawing.Size, System.Drawing">
     <value>166, 54</value>
@@ -1045,7 +1045,7 @@
     <value>0, 33</value>
   </data>
   <data name="pageEmpty.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1226, 0</value>
+    <value>1212, 0</value>
   </data>
   <data name="pageEmpty.Text" xml:space="preserve">
     <value>No channel lists</value>
@@ -1063,7 +1063,7 @@
     <value>0</value>
   </data>
   <data name="tabChannelList.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1232, 22</value>
+    <value>1218, 22</value>
   </data>
   <data name="tabChannelList.TabIndex" type="System.Int32, mscorlib">
     <value>5</value>
@@ -1147,7 +1147,7 @@
     <value>0, 26</value>
   </data>
   <data name="grpTopPanel.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 57</value>
+    <value>1402, 57</value>
   </data>
   <data name="grpTopPanel.TabIndex" type="System.Int32, mscorlib">
     <value>0</value>
@@ -1264,7 +1264,7 @@
     <value>globalImageCollection1</value>
   </data>
   <data name="&gt;&gt;globalImageCollection1.Type" xml:space="preserve">
-    <value>ChanSort.Ui.GlobalImageCollection, ChanSort, Version=1.0.7305.24811, Culture=neutral, PublicKeyToken=null</value>
+    <value>ChanSort.Ui.GlobalImageCollection, ChanSort, Version=1.0.7305.33710, Culture=neutral, PublicKeyToken=null</value>
   </data>
   <data name="&gt;&gt;gviewRight.Name" xml:space="preserve">
     <value>gviewRight</value>
@@ -1374,6 +1374,12 @@
   <data name="&gt;&gt;colFreqInMhz.Type" xml:space="preserve">
     <value>DevExpress.XtraGrid.Columns.GridColumn, DevExpress.XtraGrid.v19.2, Version=19.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a</value>
   </data>
+  <data name="&gt;&gt;colPolarity.Name" xml:space="preserve">
+    <value>colPolarity</value>
+  </data>
+  <data name="&gt;&gt;colPolarity.Type" xml:space="preserve">
+    <value>DevExpress.XtraGrid.Columns.GridColumn, DevExpress.XtraGrid.v19.2, Version=19.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a</value>
+  </data>
   <data name="&gt;&gt;colChannelOrTransponder.Name" xml:space="preserve">
     <value>colChannelOrTransponder</value>
   </data>
@@ -1428,12 +1434,6 @@
   <data name="&gt;&gt;colSymbolRate.Type" xml:space="preserve">
     <value>DevExpress.XtraGrid.Columns.GridColumn, DevExpress.XtraGrid.v19.2, Version=19.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a</value>
   </data>
-  <data name="&gt;&gt;colPolarity.Name" xml:space="preserve">
-    <value>colPolarity</value>
-  </data>
-  <data name="&gt;&gt;colPolarity.Type" xml:space="preserve">
-    <value>DevExpress.XtraGrid.Columns.GridColumn, DevExpress.XtraGrid.v19.2, Version=19.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a</value>
-  </data>
   <data name="&gt;&gt;colNetworkName.Name" xml:space="preserve">
     <value>colNetworkName</value>
   </data>
@@ -1957,7 +1957,7 @@
     <value>DevExpress.XtraEditors.XtraForm, DevExpress.Utils.v19.2, Version=19.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a</value>
   </data>
   <data name="SharedImageCollection.Timestamp" type="System.DateTime, mscorlib">
-    <value>01/01/2020 13:48:29</value>
+    <value>01/01/2020 18:44:40</value>
   </data>
   <data name="SharedImageCollection.ImageSize" type="System.Drawing.Size, System.Drawing">
     <value>16, 16</value>
@@ -2392,7 +2392,7 @@
     <value>0, 0</value>
   </data>
   <data name="grpOutputList.Size" type="System.Drawing.Size, System.Drawing">
-    <value>503, 447</value>
+    <value>503, 441</value>
   </data>
   <data name="grpOutputList.TabIndex" type="System.Int32, mscorlib">
     <value>0</value>
@@ -2773,7 +2773,7 @@
     <value>Signal source</value>
   </data>
   <data name="gridRight.Size" type="System.Drawing.Size, System.Drawing">
-    <value>903, 374</value>
+    <value>889, 368</value>
   </data>
   <data name="gridRight.TabIndex" type="System.Int32, mscorlib">
     <value>1</value>
@@ -2794,7 +2794,7 @@
     <value>Bottom</value>
   </data>
   <data name="lblHotkeyRight.Location" type="System.Drawing.Point, System.Drawing">
-    <value>2, 428</value>
+    <value>2, 422</value>
   </data>
   <data name="lblHotkeyRight.Padding" type="System.Windows.Forms.Padding, System.Windows.Forms">
     <value>2, 2, 2, 2</value>
@@ -2986,7 +2986,7 @@
     <value>2, 21</value>
   </data>
   <data name="panelControl3.Size" type="System.Drawing.Size, System.Drawing">
-    <value>903, 33</value>
+    <value>889, 33</value>
   </data>
   <data name="panelControl3.TabIndex" type="System.Int32, mscorlib">
     <value>0</value>
@@ -3010,7 +3010,7 @@
     <value>0, 0</value>
   </data>
   <data name="grpInputList.Size" type="System.Drawing.Size, System.Drawing">
-    <value>907, 447</value>
+    <value>893, 441</value>
   </data>
   <data name="grpInputList.TabIndex" type="System.Int32, mscorlib">
     <value>0</value>
@@ -3034,7 +3034,7 @@
     <value>Panel2</value>
   </data>
   <data name="splitContainerControl1.Size" type="System.Drawing.Size, System.Drawing">
-    <value>1416, 447</value>
+    <value>1402, 441</value>
   </data>
   <data name="splitContainerControl1.TabIndex" type="System.Int32, mscorlib">
     <value>5</value>
diff --git a/source/changelog.md b/source/changelog.md
index ad70342..9560f72 100644
--- a/source/changelog.md
+++ b/source/changelog.md
@@ -1,6 +1,10 @@
 ChanSort Change Log 
 ===================
 
+2020-01-02
+- added support for m3u lists (SAT>IP, VLC, WinAmp, ...)
+- disabled "Lock" toggle button when the list does not support parental locks
+
 2020-01-01
 - fixed loading of Samsung .scm files (Samsung.ini file was missing in the release package)
 - added "polarity" information for Samsung .scm and .zip files