7600GT rebooting problem?!?

First I list my specs.

Mobo-Gigabyte GA-965P-DS3
Proc- Intel Core 2 Duo 6400
Ram-3gb DualChannel Corsair XMS2
PSU- HIPER HPU-4B580-MS 580W ATX12V v2.2
Video- GIGABYTE GV-NX76T256D-RH GeForce 7600GT Silent Pipe

So I'm getting these random restarts quite frequently lately and I can't seem to figure out why. I've never had this problem before and something tells me it's a GFX card issue. The problem happens when I alt tab out of WoW, as soon as I let go of tab and it goes to switch to mozilla or ventrillo it just restarts my computer. On rare occasions it happens when I click a link in mozilla or open a new program. But, WoW is almost always running when it happens even if its minimized.
I ran registry mechanic and AVG and though they found a few little things here and there it has not solved my problem.
I used to use Omega Drivers but, it doesn't seem that the owner of the site is keeping up to date anymore.
It never happened when I used his drivers so I suppose I could re download his and use them but, I like to be as up to date as possible and I'm not positive that would fix it.
Any help or suggestions would be much appreciated.