Just a couple of things, stuff you've probably already tried. Make sure the card is hooked up right (seated correctly with the auxillary power cable). Allso, d/l the 3.2 drivers if you haven't already. I'd try that to make sure, also consider DX9. When I first installed my card, it acted like what you're describing. For some reason, it did not recognize the AGP bus, so everytime I ran an AGP program it crashed my system. Upgrading fixed it.