HIS4850 gaming problem

[siliconvideo]

The system: MSI P7N SLI, E8400, 2Gig, HIS4850, 600W PS, Vista32

The problem:
While playing EQ2, after 5-60 minutes the image will suddenly begin tearing and displaying rapidly changing triangles making the game unplayable. Closing the game and restarting will not fix the problem, triangles remain. I need to completely reboot the system to get a good game back. The problem does not seem to be associated with full screen or windowed modes.

What I've tested so far:
All Catalyst drivers 8.6 through 8.8 (btw 8.8 fan control works great).
Ran Memtest, 3DMark, and Furmark exhaustively without problems
Nothing is OC'd. All stock settings.
Updated all drivers that I could find.
Verified PS is stable
Verified CPU and GPU temps are OK although I think 80C is hot for the GPU but ATI says it's OK.
Added extra cooling fan to north bridge cause the CPU has water block cooling which reduced air flow to the north bridge heat sink.
Played Halo2 to 4 hours straight without a hick-up.
GPU loading during EQ2 runs about 50%.

Now What?
To me this looks like a driver problem but other people don't seem to having this problem. I'm presently at a lost of what to look for or change. Any suggestions would be greatly appreciated.

 

[JAYDEEJOHN]

Have any pics of this? Your card could be bad, or its some wierd driver problem. Needs some pics

 

[roadrunner197069]

PSU.

How did you verify its stable? If it a good brand and new I say ok, but if its a shotty brand or old, I bet everything on it.

 

[siliconvideo]

For Jaydeejohn: here's one of many captured images. This was captured in game by the game which means the system is still up and running fine, just EQ2 is trying to alter my reality.

For roadrunner:
My power supply is an NZXT PP-600 with +12V1 @ 21A and +12V2 @ 22A. I monitored the stability with Speedfan (gives graphs over time) while running Furmark in windowed mode. Speedfan showed 12.1V while idle and dipped down to 11.9V under load conditions. I know this is not the best way to check this but I don't really feel like dragging a scope home from work to see if I can see any other transients.

The system is brand new and I've had this problem from day one.

Thanks y'all for any suggestions.