System problem.. CPU or Video card?

[abe.conway@comcast.n]

I have a new system that I'm working with:

Asus P4P800-E Deluxe
P4 3.2E (1mb cache)
eVGA 6800 GT 256MB
2x512 Corsair XMS
2x76 gb Raptors
SB Audigy 2
Antect True Power 480w

In Doom 3, I was getting major video artifacts, especially coming off the text in the game (like on the consoles within the game) and also the G in the first "Loading" screen when you first load in to the game would warp and look funky..

In 3D Mark 05, on the second set of tests, more artifacts would show.. so I figured it wasn't Doom 3.. something was overheating possibly..

I threw the video card in my main system and didn't have any problems in 3D Mark or Doom 3. So I put a 9600 Pro that I had in the new system and I do NOT get any artifacts in Doom 3, but I do get some MINOR artifacts in 3D Mark 05 - minor compared to what I WAS getting at least with the 6800. I also have the case open during this whole time (Antec Super Lan Boy).

So I reseated the heatsink on the CPU; I cleaned off the original thermal paste and applied some Artic Silver. I put the 6800 back in the system and repeated my tests. I still had major artifacts in Doom 3 and 3D Mark 05. So I put the 9600 Pro in one more time and still got MINOR video artifacts..

According to Asus Probe, idle temp for the CPU is 41c, board temp is 30c. Temps under load for the CPU was 50c, while the board temp didn't appear to go much above 30c.

Any ideas? Should I return/exchange out both the CPU and Video Card maybe?