Freeze-Up on Cutscenes/Game Events

During various games (Neverwinter Nights 2, Oblivion, Gothic 3) there will come a point in the game where a cutscene will trigger, or a game event of some type will be initiated which causes my computer to crash. Everything stops and the screen goes blank - a solid color, often gray or black. I have to power all the way down to restart - soft restarts just deliver odd beeps and no bootup begins.

Now, I was having this problem before, and I found that my RAM sticks went bad (I used Memtest 86+ and got a lot of errors). This seemed to fix it for a bit, but now I am thinking it was one of several concurrent problems.

Here is what I am *almost* certain it is NOT:

1. Heat. My CPU is at 50C, and the air is almost an icebox in the case.
2. Power Supply. I have a 650W, which should cut it. I am running 2 HDs, a DRDRW optical, and the video card (Geforce 8800GTS)
3. RAM. All new, 2gb sticks, Memtest checks out: no errors.

Sys Info:
AMD Athlon 2.4Ghz, 2GB DDR3, Geforce 8800GTS, WinXP Pro, 650W PS

Any thoughts?

 

Overheating/faulty graphics card?

 

No, not heat. 65C avg while active. It is narrowing to the GPU slowly... Heat, RAM, Drivers, Power have all been eliminated. Perhaps an RMA candidate

 

I agree with collinsl. How are you checking your temps, and is 50ºC an idle or load temp, and what is the temp of your GPU? I use this for video card temps: http://majorgeeks.com/download5796.html

Another thing I have found with a lot of video cards is they do not ramp up the cooling fan like they should. Try Riva Tuner to max out your GPU's cooling fan. It would be a simple way to eliminate heat, and you can uninstall it if you wish. http://majorgeeks.com/download737.html

Also, do you have or can you borrow a digital multimeter to test your PSU?