I just built a new system to the following specs:

2500+ Barton
Gigabyte 7VAX-A
512MB PC2700
Radeon 9600 Pro (Catalyst 3.5 drivers)
WD 120GB SE
etc etc

Whenever I try to run a game (or 3dmark for that matter) in 8x Agp, it will work for a few minutes then my PC locks up. If I turn it down to 4X, then it works fine. Heres the weird part: I found some updated chipset drivers for my mobo and installed them which seemed to fix the problem. Strange thing is, my 3d mark scores nosedived by 1000 points after doing this. After re-installing the old drivers everything was fine. Any ideas? cuz im stumped