I have a evga gtx 460 1024mb sc ee. Since the end of Jan. 2012, I keep randomly getting blue screens. I have not had a blue screen in like 5+ years. I had several blue screens but I couldnt log them due to the screen restart happening to fast. I turned that off and the last 2 blue screen errors were, system_service_exception stop: 0x00000003B and irq_not_less_or_equal stop: 0x0000000A. From what I could find and understand, it looks like the 1st error code could be related to video card. I have tried 3 different drivers, 2 betas and 1 whql. Didnt fix anything, blue screen still happened.  Second error seemed to be hardware related. Something with the kernel trying to access memory. I have only got the blue screens when playing games. The games can also freeze/lock up. The 2 games are BF3 and CoD Black Ops zombies.
I ran memtest86 100% for 10 hrs. It passed, no errors. Even ran windows memory test, no errors.
 
Vista 64 sp2
MSI P7n sli 750i
Antec 650 Earthwatts