If you play in a window and pull something over the game it repeats and creates all kinds of weirdness. This is an IM window from Trillian I dragged over the game and as you can see it repeated the IM window a bunch of times on resizing and then did a black brush when I dragged it around.
The game fixes if I bring it back to the front.
If needed I can give my dxdiag output.
