Hello, I am having an issue with my video card, an EVGA 8800gt at stock speeds with an Accelero S1 cooler + 120mm fan. The card gives me strange artifacts on the screen (could be after 5 minutes of playing or 1 hour) very similar to these http://img519.imageshack.us/img519/1125/dsc00316eu1.jpg . The card seems to produce these artifacts with only games using the unreal 3 engine, such as Bioshock and Gears of War. Apart from that, I highly doubt that it's overheating as the card tops out at 63'c under full load in a warm room, the Accelero S1 can deal plenty with it.
i've read that sometimes the 8800gt and the audigy x-fi's dont like working together...i don't know if there is any truth to this though, since i just found out about it like 20 minutes ago and i'm at work. try removing your x-fi and run driver cleaner on the x-fi drivers...its worth a shot.