No matter what game I play or settings I use my games all give me texture malfunctions after a short time playing. I get random lock ups followed by graphic anomalies(no other way to explain). If I minimize to desktop, and then go back into the games they'll play just fine for a short period and then the same problem. I thought it was specific to S.T.A.L.K.E.R, but it does it with Crysis as well. I'm not overclocking at all, and as far as I can tell there's no overheating issues. I've had this problem with the current WHQL driver as well as the new Beta driver.
I have the following other components:
motherboard: Gigabyte GA-P35-DS3P
CPU: Core 2 Duo E6850 #GHZ
Memory: 2 X 1 GB PC6400 Crucial Ballistix
Power Supply: Thermaltake 700 Watt
Sound Card: Creative ExtremeGamer
Operating System: Windows XP Professional
I had nearly the same problem you're describing in S.T.A.L.K.E.R. with my X1900XTX. No other games seemed to do it (Crysis wasn't out then). What I discovered was that it had to do with temperature. After playing about 10 minutes the card would get up to 70C and start to artifact, though it didn't lock up. Every other game I played didn't push the card hard enough to get that warm. Then I ran the scan for artifacts in ATI Tray Tools, and sure enough when it hit around 70C for a few minutes it would start to artifact. The problem usually is caused by bad VRAM. The artifacts in ATI Tray Tools scan were consistent (ie always in the same location) which really points to a bad VRAM chip. I tried cleaning the card, even reseated the HSF, upped the fan speed (which was already running higher than default thanks to ATI Tray Tools), but nothing kept it from artifacting. Fortunately I had purchased and extended warranty through the store I bought it from because of course this manifested itself about 2 weeks after the manufacturers warranty ran out.
So after that long winded explanation, I would RMA that card, it's doubtful that it's driver/software related. Especially since you say that after dropping back to the desktop and then returning to the game it works for a short while. This is a heat induced hardware issue.
I think it has to do with 800gts not running on toughpower psus. There was a post and the guy had the same problom, and a link to a sight were it said soem 8800gt's dont work with some toughpowers.
hey i've been having the same problems and i think i just found out the solution. So earlier I was experimenting with overclocking my already overclocked video card and I found out that the highger I pushed it the more often i got these texture problems. Unfortunately at the stock setting of 670 mHz, these problems still happened yet when i lowered the speed to 650, they almost altogether stopped. Hope this info helps, and good luck. you can google rivatuner for a way to change these settings