diff --git a/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnClientWrapper.cs b/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnClientWrapper.cs
index c74bb39560..51cb611f87 100644
--- a/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnClientWrapper.cs
+++ b/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnClientWrapper.cs
@@ -131,6 +131,24 @@ namespace ICSharpCode.Svn
 		}
 		#endregion
 		
+		#region Cancel support
+		bool cancel;
+		
+		public void Cancel()
+		{
+			cancel = true;
+		}
+		
+		SvnError OnCancel(IntPtr baton)
+		{
+			// TODO: lookup correct error number
+			if (cancel)
+				return SvnError.Create(1, SvnError.NoError, "User cancelled.");
+			else
+				return SvnError.NoError;
+		}
+		#endregion
+		
 		AprPoolHandle memoryPool;
 		SvnClient client;
 		Dictionary<string, Status> statusCache = new Dictionary<string, Status>(StringComparer.InvariantCultureIgnoreCase);
@@ -142,6 +160,7 @@ namespace ICSharpCode.Svn
 			memoryPool = new AprPoolHandle();
 			client = new SvnClient(memoryPool.Pool);
 			client.Context.NotifyFunc2 = new SvnDelegate(new SvnWcNotify.Func2(OnNotify));
+			client.Context.CancelFunc = new SvnDelegate(new SvnClient.CancelFunc(OnCancel));
 		}
 		
 		public void Dispose()
@@ -300,6 +319,7 @@ namespace ICSharpCode.Svn
 			// and register authorization if necessary
 			CheckNotDisposed();
 			OpenAuth();
+			cancel = false;
 			if (OperationStarted != null)
 				OperationStarted(this, new SubversionOperationEventArgs { Operation = operationName });
 		}
diff --git a/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnMessageView.cs b/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnMessageView.cs
index c9992d636e..74e49a531f 100644
--- a/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnMessageView.cs
+++ b/src/AddIns/Misc/SubversionAddIn/Project/Src/SvnMessageView.cs
@@ -42,8 +42,12 @@ namespace ICSharpCode.Svn
 			};
 			AsynchronousWaitDialog waitDialog = null;
 			client.OperationStarted += delegate(object sender, SubversionOperationEventArgs e) {
-				if (waitDialog != null)
+				if (waitDialog == null) {
 					waitDialog = AsynchronousWaitDialog.ShowWaitDialog("svn " + e.Operation);
+//					waitDialog.Cancelled += delegate {
+//						client.Cancel();
+//					};
+				}
 			};
 			client.OperationFinished += delegate {
 				if (waitDialog != null) {
diff --git a/src/Main/Base/Project/Src/Gui/Dialogs/AsynchronousWaitDialog.cs b/src/Main/Base/Project/Src/Gui/Dialogs/AsynchronousWaitDialog.cs
index 50d80cdaf9..7f8d9be8c4 100644
--- a/src/Main/Base/Project/Src/Gui/Dialogs/AsynchronousWaitDialog.cs
+++ b/src/Main/Base/Project/Src/Gui/Dialogs/AsynchronousWaitDialog.cs
@@ -106,6 +106,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 		void Run()
 		{
 			Thread.Sleep(ShowWaitDialogDelay);
+			bool isShowingDialog;
 			lock (lockObject) {
 				if (disposed)
 					return;
@@ -115,8 +116,9 @@ namespace ICSharpCode.SharpDevelop.Gui
 				UpdateTask();
 				dlg.CreateControl();
 				IntPtr h = dlg.Handle; // force handle creation
+				isShowingDialog = showingDialog;
 			}
-			if (showingDialog) {
+			if (isShowingDialog) {
 				Application.Run();
 			} else {
 				Application.Run(dlg);
@@ -250,8 +252,8 @@ namespace ICSharpCode.SharpDevelop.Gui
 			get { return showingDialog; }
 			set {
 				if (showingDialog != value) {
-					showingDialog = value;
 					lock (lockObject) {
+						showingDialog = value;
 						if (dlg != null && disposed == false) {
 							if (value) {
 								dlg.BeginInvoke(new MethodInvoker(dlg.Hide));