PC giving me strange issues

[Domingo]

Hi all, I've got kind of a weird question and I can't seem to find out the answer or where to post this either!
Starting last week, my PC's being going haywire while playing Titan Quest. It started off happening after playing for 2-3 hours, but sometimes it happens after 5 minutes. There are little graphical glitches (it looks like vsync style mini-tears) and then it suddenly hard locks.
Over the last few days, this has been happening more and more and sometimes even in Windows itself.
I'm running a Core 2 Duo E6700 with 2GB or RAM (Corsair, rated higher than I clock it) and at stock speeds (and have a Big Typhoon cooler). My temps for the PC seem okay. My temps usually in the 30's
I also have a GeForce 7900GT that I *did* overclock using coolbits, but temps on that were never over mid 50's too.
The only other thing I've done recently was install some beta nvidia drivers that I guess were for the quadro...but I driver cleaner'd those and put back some WHQL's normal ones and stopped overclocking the card altogether.
I'm running on a 750w Thermaltake PS...so I've got plenty of juice, too.
Any idea what could cause this? Could I have fried my VC?

 

[thrawn86]

no, but if you're getting video tearing then your gpu (core) is overheating. Check to make sure the cooler is unclogged, fan is spinning, and make sure you're definitely drivercleanered out and running a stable release...

 

[Domingo]

Right on. I figured it was the card, but I wasn't sure.
I'm pretty sure the fan is working fine and the temps are pretty managable.
The only time anything like this ever happened before was the day I built the system. I didn't plug in the firewire bracket and the BIOS had it enabled by default, so it was doing something similar then (visually) but the system ran okay. Now it's doing the visual craziness...and then it tends to lock or freeze off and on.
I don't know if I should pin all of this on Titan Quest or those Quadro drivers...