Random Reboot problem. Graphics drivers related?

[Seizure Explosion]

'kay so I have a computer with and eVGA nforce 4 SLI edition mainboard and a 7800 GT from the same company. Since I installed the drivers for both (with service pack 2 installed and the whole deal) I've started to see random sudden reboots for no reason. Originally I had the drivers on the CD, but My computer wouldn't shut down properly with those. So I went and wiped my HDD and did everything over but installed the latest drivers instead. Now instead of not being able to shut down without pushing a button, I get random reboots. They're not very frequent, but I was wondering if I'm doing something hidiously wrong. Could it be a heat problem? Defective hardware? I'm stumped.

 

[jbruneau]

What are some other specs of your system?? In particular, I'm interested in your PSU and RAM??

 

[D3v01D]

Have you tested your memory with Memtest86?
That's the first thing I do with a new system, even before I load the OS.