NightShades Inc

I recently installed service pack two and my games don't work (diablo 2, unreal tournament). I get an "Error 22: A critical error has occured while initializing DirectDraw." I am running a Gefore FX 5200 video card and did not have issues before service pack two. I have tried reloading the games, drivers, and have serached the web for a patch or something. Any ideas, advice, direction will be rewarded. Thank you! - Kevin