diff --git a/ICSharpCode.Decompiler/Ast/AstBuilder.cs b/ICSharpCode.Decompiler/Ast/AstBuilder.cs
index 428e99a29..54ffa78e1 100644
--- a/ICSharpCode.Decompiler/Ast/AstBuilder.cs
+++ b/ICSharpCode.Decompiler/Ast/AstBuilder.cs
@@ -125,7 +125,7 @@ namespace Decompiler
 		{
 			// create IL code mappings - used for debugger
 			if (!CSharpCodeMapping.SourceCodeMappings.ContainsKey(typeDef.FullName)) {
-				CSharpCodeMapping.SourceCodeMappings.Add(typeDef.FullName, new List<MethodMapping>());
+				CSharpCodeMapping.SourceCodeMappings.TryAdd(typeDef.FullName, new List<MethodMapping>());
 			} else {
 				CSharpCodeMapping.SourceCodeMappings[typeDef.FullName].Clear();
 			}
diff --git a/ICSharpCode.Decompiler/Ast/CSharpCodeMapping.cs b/ICSharpCode.Decompiler/Ast/CSharpCodeMapping.cs
index 22e4cdadc..91d530b8a 100644
--- a/ICSharpCode.Decompiler/Ast/CSharpCodeMapping.cs
+++ b/ICSharpCode.Decompiler/Ast/CSharpCodeMapping.cs
@@ -2,7 +2,9 @@
 // This code is distributed under MIT X11 license (for details please see \doc\license.txt)
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
+
 using ICSharpCode.Decompiler;
 
 namespace Decompiler
@@ -12,12 +14,12 @@ namespace Decompiler
 	/// </summary>
 	public static class CSharpCodeMapping
 	{
-		static Dictionary<string, List<MethodMapping>> codeMappings = new Dictionary<string, List<MethodMapping>>();
+		static ConcurrentDictionary<string, List<MethodMapping>> codeMappings = new ConcurrentDictionary<string, List<MethodMapping>>();
 		
 		/// <summary>
 		/// Stores the source codes mappings: CSharp &lt;-&gt; editor lines
 		/// </summary>
-		public static Dictionary<string, List<MethodMapping>> SourceCodeMappings {
+		public static ConcurrentDictionary<string, List<MethodMapping>> SourceCodeMappings {
 			get { return codeMappings; }
 			set { codeMappings = value; }
 		}
diff --git a/ICSharpCode.Decompiler/CodeMappings.cs b/ICSharpCode.Decompiler/CodeMappings.cs
index 3a5475f30..f4ac2ffc2 100644
--- a/ICSharpCode.Decompiler/CodeMappings.cs
+++ b/ICSharpCode.Decompiler/CodeMappings.cs
@@ -2,7 +2,9 @@
 // This code is distributed under MIT X11 license (for details please see \doc\license.txt)
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
+
 using Decompiler;
 using ICSharpCode.Decompiler.Disassembler;
 using Mono.Cecil;
@@ -39,9 +41,9 @@ namespace ICSharpCode.Decompiler
 	
 	public static class CodeMappings
 	{
-		public static Dictionary<string, List<MethodMapping>> GetStorage(DecompiledLanguages language)
+		public static ConcurrentDictionary<string, List<MethodMapping>> GetStorage(DecompiledLanguages language)
 		{
-			Dictionary<string, List<MethodMapping>> storage = null;
+			ConcurrentDictionary<string, List<MethodMapping>> storage = null;
 			
 			switch (language) {
 				case DecompiledLanguages.IL:
@@ -64,7 +66,7 @@ namespace ICSharpCode.Decompiler
 		/// <param name="sourceCodeMappings">Source code mapping storage.</param>
 		public static MethodMapping CreateCodeMapping(
 			this MethodDefinition method,
-			Dictionary<string, List<MethodMapping>> sourceCodeMappings)
+			ConcurrentDictionary<string, List<MethodMapping>> sourceCodeMappings)
 		{
 			// create IL code mappings - used in debugger
 			MethodMapping currentMethodMapping = null;
@@ -92,7 +94,7 @@ namespace ICSharpCode.Decompiler
 		/// <param name="metadataToken">Metadata token.</param>
 		/// <returns></returns>
 		public static SourceCodeMapping GetInstructionByTypeAndLine(
-			this Dictionary<string, List<MethodMapping>> codeMappings,
+			this ConcurrentDictionary<string, List<MethodMapping>> codeMappings,
 			string typeName,
 			int lineNumber,
 			out uint metadataToken)
@@ -129,7 +131,7 @@ namespace ICSharpCode.Decompiler
 		/// <param name="typeName">Type name.</param>
 		/// <param name="line">Line number.</param>
 		public static void GetSourceCodeFromMetadataTokenAndOffset(
-			this Dictionary<string, List<MethodMapping>> codeMappings,
+			this ConcurrentDictionary<string, List<MethodMapping>> codeMappings,
 			uint token,
 			int ilOffset,
 			out string typeName,
diff --git a/ICSharpCode.Decompiler/Disassembler/ILCodeMapping.cs b/ICSharpCode.Decompiler/Disassembler/ILCodeMapping.cs
index 3425b2dfc..f08d6bb92 100644
--- a/ICSharpCode.Decompiler/Disassembler/ILCodeMapping.cs
+++ b/ICSharpCode.Decompiler/Disassembler/ILCodeMapping.cs
@@ -2,6 +2,7 @@
 // This code is distributed under MIT X11 license (for details please see \doc\license.txt)
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 
 namespace ICSharpCode.Decompiler.Disassembler
@@ -11,12 +12,12 @@ namespace ICSharpCode.Decompiler.Disassembler
 	/// </summary>
 	public static class ILCodeMapping
 	{
-		static Dictionary<string, List<MethodMapping>> codeMappings = new Dictionary<string, List<MethodMapping>>();
+		static ConcurrentDictionary<string, List<MethodMapping>> codeMappings = new ConcurrentDictionary<string, List<MethodMapping>>();
 		
 		/// <summary>
 		/// Stores the source codes mappings: IL &lt;-&gt; editor lines
 		/// </summary>
-		public static Dictionary<string, List<MethodMapping>> SourceCodeMappings {
+		public static ConcurrentDictionary<string, List<MethodMapping>> SourceCodeMappings {
 			get { return codeMappings; }
 			set { codeMappings = value; }
 		}
diff --git a/ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs b/ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs
index 2804b0104..6e20cdfa0 100644
--- a/ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs
+++ b/ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs
@@ -314,7 +314,9 @@ namespace ICSharpCode.Decompiler.Disassembler
 		{
 			// create IL code mappings - used for debugger
 			if (!ILCodeMapping.SourceCodeMappings.ContainsKey(type.FullName)) {
-				ILCodeMapping.SourceCodeMappings.Add(type.FullName, new List<MethodMapping>());
+				ILCodeMapping.SourceCodeMappings.TryAdd(type.FullName, new List<MethodMapping>());
+			} else {
+				ILCodeMapping.SourceCodeMappings.Clear();
 			}
 			
 			// start writing IL
diff --git a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
index 217934a97..f080ce46a 100644
--- a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
+++ b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
@@ -1,4 +1,3 @@
-<<<<<<< HEAD
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
@@ -52,8 +51,8 @@
   <ItemGroup>
     <Compile Include="Ast\AstBuilder.cs" />
     <Compile Include="Ast\AstMethodBodyBuilder.cs" />
-    <Compile Include="Ast\CSharpCodeMapping.cs" />
     <Compile Include="Ast\CommentStatement.cs" />
+    <Compile Include="Ast\CSharpCodeMapping.cs" />
     <Compile Include="Ast\DecompilerContext.cs" />
     <Compile Include="Ast\NameVariables.cs" />
     <Compile Include="Ast\NRefactoryExtensions.cs" />
@@ -72,132 +71,8 @@
     <Compile Include="CecilExtensions.cs" />
     <Compile Include="CodeMappings.cs" />
     <Compile Include="DecompilerException.cs" />
-    <Compile Include="Disassembler\ILCodeMapping.cs" />
-    <Compile Include="Disassembler\DisassemblerHelpers.cs" />
-    <Compile Include="Disassembler\ILStructure.cs" />
-    <Compile Include="Disassembler\MethodBodyDisassembler.cs" />
-    <Compile Include="Disassembler\ReflectionDisassembler.cs" />
-    <Compile Include="FlowAnalysis\ControlFlowEdge.cs" />
-    <Compile Include="FlowAnalysis\ControlFlowGraph.cs" />
-    <Compile Include="FlowAnalysis\ControlFlowGraphBuilder.cs" />
-    <Compile Include="FlowAnalysis\ControlFlowNode.cs" />
-    <Compile Include="FlowAnalysis\ControlStructureDetector.cs" />
-    <Compile Include="FlowAnalysis\OpCodeInfo.cs" />
-    <Compile Include="FlowAnalysis\SimplifyByRefCalls.cs" />
-    <Compile Include="FlowAnalysis\SsaBlock.cs" />
-    <Compile Include="FlowAnalysis\SsaForm.cs" />
-    <Compile Include="FlowAnalysis\SsaFormBuilder.cs" />
-    <Compile Include="FlowAnalysis\SsaInstruction.cs" />
-    <Compile Include="FlowAnalysis\SsaOptimization.cs" />
-    <Compile Include="FlowAnalysis\SsaVariable.cs" />
-    <Compile Include="FlowAnalysis\TransformToSsa.cs" />
-    <Compile Include="GraphVizGraph.cs" />
-    <Compile Include="ILAst\ILAstBuilder.cs" />
-    <Compile Include="ILAst\ILAstOptimizer.cs" />
-    <Compile Include="ILAst\ILAstTypes.cs" />
-    <Compile Include="ILAst\ILCodes.cs" />
-    <Compile Include="ILAst\TypeAnalysis.cs" />
-    <Compile Include="ITextOutput.cs" />
-    <Compile Include="Options.cs" />
-    <Compile Include="PlainTextOutput.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <None Include="Properties\AssemblyInfo.template.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\Mono.Cecil\Mono.Cecil.csproj">
-      <Project>{D68133BD-1E63-496E-9EDE-4FBDBF77B486}</Project>
-      <Name>Mono.Cecil</Name>
-    </ProjectReference>
-    <ProjectReference Include="..\NRefactory\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">
-      <Project>{3B2A5653-EC97-4001-BB9B-D90F1AF2C371}</Project>
-      <Name>ICSharpCode.NRefactory</Name>
-    </ProjectReference>
-  </ItemGroup>
-  <ItemGroup>
-    <Folder Include="Ast" />
-    <Folder Include="Ast\Transforms" />
-    <Folder Include="Disassembler" />
-    <Folder Include="ILAst" />
-  </ItemGroup>
-  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.Targets" />
-  <Target Name="BeforeBuild">
-    <MSBuild Projects="$(MSBuildProjectDirectory)\..\BuildTools\UpdateAssemblyInfo\UpdateAssemblyInfo.csproj" Targets="Build" Properties="Configuration=Debug" />
-    <Exec WorkingDirectory="$(MSBuildProjectDirectory)\..\BuildTools\UpdateAssemblyInfo\bin\Debug" Command="UpdateAssemblyInfo.exe --branchname $(BranchName)" Timeout="60000" Condition=" '$(BranchName)' != '' " />
-    <Exec WorkingDirectory="$(MSBuildProjectDirectory)\..\BuildTools\UpdateAssemblyInfo\bin\Debug" Command="UpdateAssemblyInfo.exe" Timeout="60000" Condition=" '$(BranchName)' == '' " />
-  </Target>
-=======
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
-  <PropertyGroup>
-    <ProjectGuid>{984CC812-9470-4A13-AFF9-CC44068D666C}</ProjectGuid>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <OutputType>Library</OutputType>
-    <RootNamespace>ICSharpCode.Decompiler</RootNamespace>
-    <AssemblyName>ICSharpCode.Decompiler</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
-    <TargetFrameworkProfile>Client</TargetFrameworkProfile>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <AllowUnsafeBlocks>False</AllowUnsafeBlocks>
-    <NoStdLib>False</NoStdLib>
-    <WarningLevel>4</WarningLevel>
-    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Platform)' == 'AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <RegisterForComInterop>False</RegisterForComInterop>
-    <GenerateSerializationAssemblies>Auto</GenerateSerializationAssemblies>
-    <BaseAddress>4194304</BaseAddress>
-    <FileAlignment>4096</FileAlignment>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
-    <OutputPath>bin\Debug\</OutputPath>
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>Full</DebugType>
-    <Optimize>False</Optimize>
-    <CheckForOverflowUnderflow>True</CheckForOverflowUnderflow>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
-    <OutputPath>bin\Release\</OutputPath>
-    <DebugSymbols>False</DebugSymbols>
-    <DebugType>None</DebugType>
-    <Optimize>True</Optimize>
-    <CheckForOverflowUnderflow>False</CheckForOverflowUnderflow>
-    <DefineConstants>TRACE</DefineConstants>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="System" />
-    <Reference Include="System.Core">
-      <RequiredTargetFramework>3.5</RequiredTargetFramework>
-    </Reference>
-    <Reference Include="System.Xml" />
-    <Reference Include="System.Xml.Linq">
-      <RequiredTargetFramework>3.5</RequiredTargetFramework>
-    </Reference>
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="Ast\AstBuilder.cs" />
-    <Compile Include="Ast\AstMethodBodyBuilder.cs" />
-    <Compile Include="Ast\CommentStatement.cs" />
-    <Compile Include="Ast\DecompilerContext.cs" />
-    <Compile Include="Ast\NameVariables.cs" />
-    <Compile Include="Ast\NRefactoryExtensions.cs" />
-    <Compile Include="Ast\TextOutputFormatter.cs" />
-    <Compile Include="Ast\Transforms\ContextTrackingVisitor.cs" />
-    <Compile Include="Ast\Transforms\ConvertConstructorCallIntoInitializer.cs" />
-    <Compile Include="Ast\Transforms\DelegateConstruction.cs" />
-    <Compile Include="Ast\Transforms\ReplaceMethodCallsWithOperators.cs" />
-    <Compile Include="Ast\Transforms\PushNegation.cs" />
-    <Compile Include="Ast\Transforms\RemoveDeadLabels.cs" />
-    <Compile Include="Ast\Transforms\RemoveEmptyElseBody.cs" />
-    <Compile Include="Ast\Transforms\RemoveGotos.cs" />
-    <Compile Include="Ast\Transforms\RestoreLoop.cs" />
-    <Compile Include="Ast\Transforms\TransformationPipeline.cs" />
-    <Compile Include="Ast\Transforms\UsingStatementTransform.cs" />
-    <Compile Include="CecilExtensions.cs" />
-    <Compile Include="DecompilerException.cs" />
     <Compile Include="Disassembler\DisassemblerHelpers.cs" />
+    <Compile Include="Disassembler\ILCodeMapping.cs" />
     <Compile Include="Disassembler\ILStructure.cs" />
     <Compile Include="Disassembler\MethodBodyDisassembler.cs" />
     <Compile Include="Disassembler\ReflectionDisassembler.cs" />
@@ -250,5 +125,4 @@
     <Exec WorkingDirectory="$(MSBuildProjectDirectory)\..\BuildTools\UpdateAssemblyInfo\bin\Debug" Command="UpdateAssemblyInfo.exe --branchname $(BranchName)" Timeout="60000" Condition=" '$(BranchName)' != '' " />
     <Exec WorkingDirectory="$(MSBuildProjectDirectory)\..\BuildTools\UpdateAssemblyInfo\bin\Debug" Command="UpdateAssemblyInfo.exe" Timeout="60000" Condition=" '$(BranchName)' == '' " />
   </Target>
->>>>>>> 758f18c73f2667591014666e73ee139fe449c022
 </Project>
\ No newline at end of file
diff --git a/ILSpy.sln b/ILSpy.sln
index 3bb9f43f4..3310fac98 100644
--- a/ILSpy.sln
+++ b/ILSpy.sln
@@ -1,15 +1,15 @@
 
 Microsoft Visual Studio Solution File, Format Version 11.00
 # Visual Studio 2010
-# SharpDevelop 4.1.0.7302-alpha
+# SharpDevelop 4.1.0.7279-alpha
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Debugger", "Debugger", "{1DEB3B4E-03AC-437C-821D-B09FBFCC3E5B}"
 	ProjectSection(SolutionItems) = postProject
 	EndProjectSection
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Debugger.Core", "Debugger\Debugger.Core\Debugger.Core.csproj", "{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}"
-EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ILSpy.Debugger", "Debugger\ILSpy.Debugger\ILSpy.Debugger.csproj", "{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Debugger.Core", "Debugger\Debugger.Core\Debugger.Core.csproj", "{1D18D788-F7EE-4585-A23B-34DC8EC63CB8}"
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ILSpy", "ILSpy\ILSpy.csproj", "{1E85EFF9-E370-4683-83E4-8A3D063FF791}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ICSharpCode.TreeView", "SharpTreeView\ICSharpCode.TreeView.csproj", "{DDE2A481-8271-4EAC-A330-8FA6A38D13D1}"
@@ -106,7 +106,7 @@ Global
 		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A}.Release|Any CPU.ActiveCfg = Release|x86
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
-		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A} = {1DEB3B4E-03AC-437C-821D-B09FBFCC3E5B}
 		{1D18D788-F7EE-4585-A23B-34DC8EC63CB8} = {1DEB3B4E-03AC-437C-821D-B09FBFCC3E5B}
+		{6D3D0F0D-348D-456A-A6ED-E9BD5EFABB6A} = {1DEB3B4E-03AC-437C-821D-B09FBFCC3E5B}
 	EndGlobalSection
 EndGlobal