Graphical abnormalities w/ GF 7900 gtx

I just recently bought a BFG Tech Geforec 7900 gtx 512 and I have been getting all kinds of weird graphical abnoramlities with it. I condiser myself experinced with PC but everything I've tried has not gotten rid of these abnormalities. My build is as follows, AMD Athlon 64 4000+, GF 7900 gtx, 2GB Corsair XMS, ASUS a8n-sli premium, 1x WD Raptor, 2x 300GB Seagate Barracudas and all powered by a Seasonice S-12 600 watt psu. All the voltages are within 5%. And I have the latest drivers for everything. I am completely stumped with this issue.

I have some screenies of these abnormalities.
Abnormality Screen 1
Abnormality Screen 2
The abnormailties in these 2 screens are the most common and show up in all the games I play but apear in random locations.
Abnormality Screen 3
Now this abnormality only aprears in City of Villains where the edges of various polies are streched forever in a single direction.

That looks pretty bad. You need to try that card in another machine if possible.....if not, then like Prozac said, you might have to get an RMA on it.

If the card is undervoltage it should give you a messege on the main screen that the voltage is insufficient. If so then the card would automatically sets to the lowest settings. A minimum of 400watts is needed to run a single 7900GTX. Try the lowest settings and se if that works, if not then try another pc that has enough power to run it. If it's still doing it then get it replaced.

So you finally got your A64, and you broke 7k in 3DMark05.

Meanwhile, my score has gone down from 2265 to about 1500. I think that I've damaged my video card with the overclocking. A week ago, I scored 2200 with the same setup. I don't care too much because I can still play my games at 10 FPS, so I'm happy.