diff --git a/src/Libraries/AvalonDock/AvalonDock.dll b/src/Libraries/AvalonDock/AvalonDock.dll
index 57f4b1e24b..0adc2c8efd 100644
Binary files a/src/Libraries/AvalonDock/AvalonDock.dll and b/src/Libraries/AvalonDock/AvalonDock.dll differ
diff --git a/src/Main/Base/Project/Src/Gui/IWorkbench.cs b/src/Main/Base/Project/Src/Gui/IWorkbench.cs
index 0931e5677e..c841b1db00 100644
--- a/src/Main/Base/Project/Src/Gui/IWorkbench.cs
+++ b/src/Main/Base/Project/Src/Gui/IWorkbench.cs
@@ -140,11 +140,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 		/// </summary>
 		PadDescriptor GetPad(Type type);
 		
-		/// <summary>
-		/// Closes the IViewContent content when content is open.
-		/// </summary>
-		void CloseContent(IViewContent content);
-		
 		/// <summary>
 		/// Closes all views inside the workbench.
 		/// </summary>
diff --git a/src/Main/Base/Project/Src/Gui/IWorkbenchLayout.cs b/src/Main/Base/Project/Src/Gui/IWorkbenchLayout.cs
index 11e3008cad..be42f1bbb1 100644
--- a/src/Main/Base/Project/Src/Gui/IWorkbenchLayout.cs
+++ b/src/Main/Base/Project/Src/Gui/IWorkbenchLayout.cs
@@ -79,11 +79,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 		/// </summary>
 		bool IsVisible(PadDescriptor padContent);
 		
-		/// <summary>
-		/// Re-initializes all components of the layout manager.
-		/// </summary>
-		void RedrawAllComponents();
-		
 		/// <summary>
 		/// Shows a new <see cref="IViewContent"/>.
 		/// </summary>
diff --git a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonDockLayout.cs b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonDockLayout.cs
index 8496281d95..45fc80a749 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonDockLayout.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonDockLayout.cs
@@ -29,6 +29,10 @@ namespace ICSharpCode.SharpDevelop.Gui
 		List<IWorkbenchWindow> workbenchWindows = new List<IWorkbenchWindow>();
 		internal bool Busy;
 		
+		public WpfWorkbench Workbench {
+			get { return workbench; }
+		}
+		
 		public DockingManager DockingManager {
 			get { return dockingManager; }
 		}
@@ -39,12 +43,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 			dockingManager.PropertyChanged += dockingManager_PropertyChanged;
 		}
 		
-		public void OnWorkbenchWindowClosed(AvalonWorkbenchWindow window)
-		{
-			workbenchWindows.Remove(window);
-			documentPane.Items.Remove(window);
-		}
-		
 		void dockingManager_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
 		{
 			if (e.PropertyName == "ActiveContent") {
@@ -153,10 +151,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 			return pads[padContent].IsVisible;
 		}
 		
-		public void RedrawAllComponents()
-		{
-		}
-		
 		public IWorkbenchWindow ShowView(IViewContent content)
 		{
 			AvalonWorkbenchWindow window = new AvalonWorkbenchWindow(this);
@@ -165,9 +159,15 @@ namespace ICSharpCode.SharpDevelop.Gui
 			window.ViewContents.AddRange(content.SecondaryViewContents);
 			documentPane.Items.Add(window);
 			dockingManager.Show(window);
+			window.Closed += window_Closed;
 			return window;
 		}
 		
+		void window_Closed(object sender, EventArgs e)
+		{
+			workbenchWindows.Remove((IWorkbenchWindow)sender);
+		}
+		
 		public void LoadConfiguration()
 		{
 			try {
diff --git a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonWorkbenchWindow.cs b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonWorkbenchWindow.cs
index a1edf72afc..b6720d839b 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonWorkbenchWindow.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/AvalonWorkbenchWindow.cs
@@ -293,6 +293,8 @@ namespace ICSharpCode.SharpDevelop.Gui
 			content.TabPageTextChanged += OnTabPageTextChanged;
 			content.TitleNameChanged   += OnTitleNameChanged;
 			content.IsDirtyChanged     += OnIsDirtyChanged;
+			
+			this.dockLayout.Workbench.OnViewOpened(new ViewContentEventArgs(content));
 		}
 		
 		void UnregisterContent(IViewContent content)
@@ -302,6 +304,8 @@ namespace ICSharpCode.SharpDevelop.Gui
 			content.TabPageTextChanged -= OnTabPageTextChanged;
 			content.TitleNameChanged   -= OnTitleNameChanged;
 			content.IsDirtyChanged     -= OnIsDirtyChanged;
+			
+			this.dockLayout.Workbench.OnViewClosed(new ViewContentEventArgs(content));
 		}
 		
 		void OnTabPageTextChanged(object sender, EventArgs e)
@@ -309,9 +313,19 @@ namespace ICSharpCode.SharpDevelop.Gui
 			RefreshTabPageTexts();
 		}
 		
+		bool forceClose;
+		
 		public bool CloseWindow(bool force)
 		{
-			if (!force && this.IsDirty) {
+			forceClose = force;
+			Close();
+			return this.ViewContents.Count == 0;
+		}
+		
+		protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
+		{
+			base.OnClosing(e);
+			if (!e.Cancel && !forceClose && this.IsDirty) {
 				MessageBoxResult dr = MessageBox.Show(
 					ResourceService.GetString("MainWindow.SaveChangesMessage"),
 					ResourceService.GetString("MainWindow.SaveChangesMessageHeader") + " " + Title + " ?",
@@ -338,14 +352,17 @@ namespace ICSharpCode.SharpDevelop.Gui
 					case MessageBoxResult.No:
 						break;
 					case MessageBoxResult.Cancel:
-						return false;
+						e.Cancel = true;
+						break;
 				}
 			}
-
-			dockLayout.OnWorkbenchWindowClosed(this);
+		}
+		
+		protected override void OnClosed()
+		{
+			base.OnClosed();
 			Dispose();
 			CommandManager.InvalidateRequerySuggested();
-			return true;
 		}
 		
 		public void RedrawContent()
diff --git a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
index 51b27a5ac9..533f6e2b2d 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
@@ -31,13 +31,22 @@ namespace ICSharpCode.SharpDevelop.Gui
 		public event EventHandler ActiveContentChanged;
 		public event ViewContentEventHandler ViewOpened;
 		
-		void OnViewOpened(ViewContentEventArgs e)
+		internal void OnViewOpened(ViewContentEventArgs e)
 		{
 			if (ViewOpened != null) {
 				ViewOpened(this, e);
 			}
 		}
+		
 		public event ViewContentEventHandler ViewClosed;
+		
+		internal void OnViewClosed(ViewContentEventArgs e)
+		{
+			if (ViewClosed != null) {
+				ViewClosed(this, e);
+			}
+		}
+		
 		public event System.Windows.Forms.KeyEventHandler ProcessCommandKey;
 		
 		public System.Windows.Forms.IWin32Window MainWin32Window { get; private set; }
@@ -100,7 +109,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 		
 		public ICollection<IViewContent> ViewContentCollection {
 			get {
-				return WorkbenchWindowCollection.SelectMany(w => w.ViewContents).ToList().ToArray();
+				return WorkbenchWindowCollection.SelectMany(w => w.ViewContents).ToList().AsReadOnly();
 			}
 		}
 		
@@ -162,6 +171,9 @@ namespace ICSharpCode.SharpDevelop.Gui
 		
 		void OnActiveWindowChanged(object sender, EventArgs e)
 		{
+			if (closeAll)
+				return;
+			
 			if (workbenchLayout != null) {
 				this.ActiveContent = workbenchLayout.ActiveContent;
 				this.ActiveWorkbenchWindow = workbenchLayout.ActiveWorkbenchWindow;
@@ -235,7 +247,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 			
 			WorkbenchLayout.ShowView(content);
 			content.WorkbenchWindow.SelectWindow();
-			OnViewOpened(new ViewContentEventArgs(content));
 		}
 		
 		public void ShowPad(PadDescriptor content)
@@ -264,12 +275,22 @@ namespace ICSharpCode.SharpDevelop.Gui
 			return null;
 		}
 		
-		public void CloseContent(IViewContent content)
-		{
-		}
+		/// <summary>
+		/// Flag used to prevent repeated ActiveWindowChanged events during CloseAllViews().
+		/// </summary>
+		bool closeAll;
 		
 		public void CloseAllViews()
 		{
+			try {
+				closeAll = true;
+				foreach (IWorkbenchWindow window in this.WorkbenchWindowCollection.ToArray()) {
+					window.CloseWindow(false);
+				}
+			} finally {
+				closeAll = false;
+				OnActiveWindowChanged(this, EventArgs.Empty);
+			}
 		}
 		
 		public void RedrawAllComponents()
diff --git a/src/Main/Core/Project/Src/Services/ResourceService/ResourceService.cs b/src/Main/Core/Project/Src/Services/ResourceService/ResourceService.cs
index 14a0ce6fea..2c5b20ba79 100644
--- a/src/Main/Core/Project/Src/Services/ResourceService/ResourceService.cs
+++ b/src/Main/Core/Project/Src/Services/ResourceService/ResourceService.cs
@@ -50,6 +50,8 @@ namespace ICSharpCode.Core
 			}
 		}
 		
+		static readonly object loadLock = new object();
+		
 		/// <summary>English strings (list of resource managers)</summary>
 		static List<ResourceManager> strings = new List<ResourceManager>();
 		/// <summary>Neutral/English images (list of resource managers)</summary>
@@ -178,33 +180,34 @@ namespace ICSharpCode.Core
 		
 		static void LoadLanguageResources(string language)
 		{
-			if (ClearCaches != null)
-				ClearCaches(null, EventArgs.Empty);
-			
-			try {
-				Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(language);
-			} catch (Exception) {
+			lock (loadLock) {
 				try {
-					Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(language.Split('-')[0]);
-				} catch (Exception) {}
-			}
-			
-			localStrings = Load(stringResources, language);
-			if (localStrings == null && language.IndexOf('-') > 0) {
-				localStrings = Load(stringResources, language.Split('-')[0]);
-			}
-			
-			localIcons = Load(imageResources, language);
-			if (localIcons == null && language.IndexOf('-') > 0) {
-				localIcons = Load(imageResources, language.Split('-')[0]);
-			}
-			
-			localStringsResMgrs.Clear();
-			localIconsResMgrs.Clear();
-			currentLanguage = language;
-			foreach (ResourceAssembly ra in resourceAssemblies) {
-				ra.Load();
+					Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(language);
+				} catch (Exception) {
+					try {
+						Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(language.Split('-')[0]);
+					} catch (Exception) {}
+				}
+				
+				localStrings = Load(stringResources, language);
+				if (localStrings == null && language.IndexOf('-') > 0) {
+					localStrings = Load(stringResources, language.Split('-')[0]);
+				}
+				
+				localIcons = Load(imageResources, language);
+				if (localIcons == null && language.IndexOf('-') > 0) {
+					localIcons = Load(imageResources, language.Split('-')[0]);
+				}
+				
+				localStringsResMgrs.Clear();
+				localIconsResMgrs.Clear();
+				currentLanguage = language;
+				foreach (ResourceAssembly ra in resourceAssemblies) {
+					ra.Load();
+				}
 			}
+			if (ClearCaches != null)
+				ClearCaches(null, EventArgs.Empty);
 		}
 		
 		static Hashtable Load(string fileName)
@@ -241,68 +244,72 @@ namespace ICSharpCode.Core
 		/// </exception>
 		public static string GetString(string name)
 		{
-			if (localStrings != null && localStrings[name] != null) {
-				return localStrings[name].ToString();
-			}
-			
-			string s = null;
-			foreach (ResourceManager resourceManger in localStringsResMgrs) {
-				try {
-					s = resourceManger.GetString(name);
-				}
-				catch (Exception) { }
-
-				if (s != null) {
-					break;
+			lock (loadLock) {
+				if (localStrings != null && localStrings[name] != null) {
+					return localStrings[name].ToString();
 				}
-			}
-			
-			if (s == null) {
-				foreach (ResourceManager resourceManger in strings) {
+				
+				string s = null;
+				foreach (ResourceManager resourceManger in localStringsResMgrs) {
 					try {
 						s = resourceManger.GetString(name);
 					}
 					catch (Exception) { }
-					
+
 					if (s != null) {
 						break;
 					}
 				}
+				
+				if (s == null) {
+					foreach (ResourceManager resourceManger in strings) {
+						try {
+							s = resourceManger.GetString(name);
+						}
+						catch (Exception) { }
+						
+						if (s != null) {
+							break;
+						}
+					}
+				}
+				if (s == null) {
+					throw new ResourceNotFoundException("string >" + name + "<");
+				}
+				
+				return s;
 			}
-			if (s == null) {
-				throw new ResourceNotFoundException("string >" + name + "<");
-			}
-			
-			return s;
 		}
 		
 		public static object GetImageResource(string name)
 		{
-			object iconobj = null;
-			if (localIcons != null && localIcons[name] != null) {
-				iconobj = localIcons[name];
-			} else {
-				foreach (ResourceManager resourceManger in localIconsResMgrs) {
-					iconobj = resourceManger.GetObject(name);
-					if (iconobj != null) {
-						break;
-					}
-				}
-				
-				if (iconobj == null) {
-					foreach (ResourceManager resourceManger in icons) {
-						try {
-							iconobj = resourceManger.GetObject(name);
-						}
-						catch (Exception) { }
-
+			lock (loadLock) {
+				object iconobj = null;
+				if (localIcons != null && localIcons[name] != null) {
+					iconobj = localIcons[name];
+				} else {
+					foreach (ResourceManager resourceManger in localIconsResMgrs) {
+						iconobj = resourceManger.GetObject(name);
 						if (iconobj != null) {
 							break;
 						}
 					}
+					
+					if (iconobj == null) {
+						foreach (ResourceManager resourceManger in icons) {
+							try {
+								iconobj = resourceManger.GetObject(name);
+							}
+							catch (Exception) { }
+
+							if (iconobj != null) {
+								break;
+							}
+						}
+					}
 				}
+				return iconobj;
 			}
-			return iconobj;
 		}
 	}
 }
diff --git a/src/Main/ICSharpCode.Core.Presentation/PresentationResourceService.cs b/src/Main/ICSharpCode.Core.Presentation/PresentationResourceService.cs
index 17da34a931..298a80f148 100644
--- a/src/Main/ICSharpCode.Core.Presentation/PresentationResourceService.cs
+++ b/src/Main/ICSharpCode.Core.Presentation/PresentationResourceService.cs
@@ -22,6 +22,18 @@ namespace ICSharpCode.Core.Presentation
 	{
 		static readonly Dictionary<string, BitmapSource> bitmapCache = new Dictionary<string, BitmapSource>();
 		
+		static PresentationResourceService()
+		{
+			ResourceService.ClearCaches += ResourceService_ClearCaches;
+		}
+		
+		static void ResourceService_ClearCaches(object sender, EventArgs e)
+		{
+			lock (bitmapCache) {
+				bitmapCache.Clear();
+			}
+		}
+		
 		/// <summary>
 		/// Creates a new System.Windows.Controls.Image object containing the image with the
 		/// specified resource name.