WPF Application is slow / jerky whilst being moved

I have a rather basic shell of a WPF app that I am creating. When I move it using the DragMove() function the app moves properly but seems to "jerk" a lot. It seems to me that the redraw rate is very low making the application look slow and unresponsive.

Currently there is no "code" besides a call to DragMove().

The XAML consists of an outer border with rounded corners and drop shadow set to RenderingBias="Performance". There is also a small gradient on the title bar and a path. But even commenting these out of the code still开发者_开发知识库 makes the app appear jerky and slow whilst moving.

Note I have ran this in Release and outside the debugger too.

From experience, try removing the drop shadow and you'll see much better perfomance.

http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/99faecec-395f-4a47-92ee-620b11c39ae7