During our testing phase we discovered an issue that appears to be within the Infragistics libraries.  I didn't see anything obvious in the API's that would provide a work around for this.  We are using infragistics v13.2.  Any suggestions on a solution?

Scenario:

User clicks on the HeaderArea and drags the dialog window

While this is occurring we programmatically close the dialog 

Exception Thrown:

UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object.
at Infragistics.Controls.Interactions.XamDialogWindow.HeaderArea_MouseMove(Object sender, MouseEventArgs e)
at System.Windows.Input.MouseEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
at System.Windows.Input.InputManager.ProcessStagingArea()
at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
at System.Windows.Input.MouseDevice.Synchronize()
at System.Windows.Input.MouseDevice.OnHitTestInvalidatedAsync(Object sender, EventArgs e)
at System.Windows.Input.InputManager.HitTestInvalidatedAsyncCallback(Object arg)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler);