It looks like video driver weirdness to me - I usually check to make sure I have the latest driver installed, then I use device manager to delete it, reboot, and let windows re-install it on the fly - If the problem persists, I'd try changing hardware acceleration settings or color depth/screen resolution until problem stops. Unless it's a conflict with something you've recently installed, I'd expect the problem to clear up. (Also, if your version of windows has "use animations" enabled, you might try turning them off) Good luck, & I hope it clears up.....