Computer Freezes Playing Games

[buffdaddy110]

After playing a game for awhile my monitor will pixelate and put itself into powersave mode, and the PC will lock up. I have to shut the PC off with the power button and turn it back on with the power button. I've tried a new monitor, memory, hard drive, and bios upgrade. The only thing I haven't changed is the CPU, sound card, power supply, video card, or motherboard. I don't do any overclocking and the PC is running cool. Also, all drivers are current. This is the hardware I currently have;

Athlon 64 3400+ (newcastle)
MSI K8N NEO Platinum NForce 3
Maxtor 300 Gb SATA Diamond Max 10
2 X 512 OCZ EL PC3200
Sound Blaster Audigy 2 ZS
OCZ 420 Watt Dual Adjustable Rail Power Supply
Windows Xp Pro with SP2
BFG 6800 GT

 

[buffdaddy110]

I noticed my 3.3 volt rail on my power supply is at 3.06. I heard it should really never be below 3.3. Could this be a cause?

 

[patio]

Seeing as your system has more than enough gusto for gaming yes i would suspect the PSU...
Just to be sure DLoad and run memtest for that RAM, test one stick at a time and let it run for a few hours.
Any errors means faulty RAM and it should be replaced.

patio.