8800 GTS G92 graphic crash

Ok i own this card for about 4 month, and suddenly i had experienced a few graphic crash in a day playing games like assassin creed, cnc3, UT3 and Turok (bad graphic even with high setting). i dont know what cause the crash since i keep the card temperature at 62~65C with 85% fan speed and when the graphic start to crash red line starting to appear. the games still working for about 30~45 sec then suddenly poof graphic hang. so i hope i can get certain info on the thing that cause the problem from tomshardware forum expert. my pc is not power hungry since i use C2D@6300 2Gigs kingston value ram 1 160gb hard disk, 1 dvdrom/writer, 1 combo drive. no overclocking. my PSU is ODIN GT 550W. from my own knowledge i doubt lack of power is the problem since my gigabyte power tuner detect that my pc only use between 100~200W on load. From my own opinion i suggest either the card has become faulty or my window XP is having problem. if u guys have other opinion on the matter please tell me and guide me on fixing this crash problem.


Edited: im using forceware version 169.21 when it start to crash and then i use 174.74 beta driver to check if theres a different and quite sad it make it worse so i revert to the previous one.