Hi, I've some trouble with Tim's FloatableWindow. (<--SourceCode & DLLs) It throws the following Exception once closed the control. Object reference not set to an instance of an object in System.Windows.Controls.FloatableWindow.b__0(Object s, EventArgs args) in System.Windows.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args) in MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, String eventName) First I created a control by using the FloatableWindow template, And then i just created the Window on CodeBehind. private void Button_Click_1(object sender, RoutedEventArgs e) { FloatableWindow1 f1 = new FloatableWindow1();//TheTemplatedOne f1.ShowDialog(); } private void Button_Click_2(object sender, RoutedEventArgs e) { FloatableWindow f = new FloatableWindow(); f.Height = 100; f.Width = 100; f.Background = new SolidColorBrush(Colors.Yellow); f.ShowDialog(); } But stills the same issue... Im not trying to access any information on the Closed EventHandler. Im running v3.0.40624.4 Release of the dll on SL v3.0.50106.0 in a C# project w/RiaServices Thanks