Use invoke so that we run code on the UI thread (no idea how this was working before)

WindowsFormsSample/WindowsFormsSample/ChatForm.cs

@@ -102,8 +102,13 @@ namespace WindowsFormsSample
         }
 
         private void Log(Color color, string message)
+        {
+            Action callback = () =>
             {
                 messagesList.Items.Add(new LogMessage(color, message));
+            };
+
+            Invoke(callback);
         }
 
         private class LogMessage