Hi all i have a diamond stealth III and anytime i would try to play any quake engine games such as quake 3 rtcw medal of honor my pc would lock up when it tryed to iniatilize the game. I found this awesome program called display doctor by scitech and since installing and using it these games work like a charm. it can be found at http://www.scitechsoft.com/down_sdd_win.html
I dont know if this will help anyone else but i hope it does. I tried everything before i found this i mean newest drivers glsetup blah blah blah its worth a shot. Good Luck.