Comp screwed

[DragoNs]

cant seem to figure out the problem with my computer, when ever im playing WoW or DAoC both fullscreen i seem to crash ie screen goes black or sometimes the screen splits in 2 and pixalates or moniter just goes black. I have reformated. Edit - Crashes or does these errors after about 30 mins of gameplay - also I sometimes get ATI - VPU RECOVERY ERROR

Computer is
P4 2.8 533fsb
ASUS P4S800
ATI Radeon 9800 PRO 128mb
80gb WD ATA
Enermax 485w

I just got my video card RMAed and same problem.... then i bought a new PSU same thing, and i dont think its software because i have reformatted like 4-5 times, same problems, can anyone help??

I have replaced the hsf on the videocard with a kwvc-3 i have used a box fan on the side.. still crashes ... ive done ram test 5 and 8 looped 20 times.. rams fine... CPU seems to have good heat.. bout 40C. Videocard is new.. RMA'd so .. i think its the motherboards AGP slot.. any ideas?

[cirthix]

clean the contacts on the videocard and screw it into your case. same thing happens to me if the vid card wiggles a bit, but i dont use a case ;)

[DragoNs]

I cleaned everything when i was installing the kwvc-3 on it.