IRQL not less or equal BSOD

After the April 8th Vista update, my computer will blue screen after 2-6 hrs of gaming/activity. Once it bluescreens, it will restart and BSOD again after a few minutes. Each time it restarts, the BSOD comes quicker until my MOBO (P35-DSL3) resets the bios. The mobo does this automatically if windows fails to load after several times. It will BSOD in safe mode, as well etc.

But if I shut it down and wait an ~hr, it will work fine for another 2-6 hrs, and then the process repeats. I've reinstalled the video card driver, ran memory tests (one failed, but when I reran and reran and reran, all of them passed). During one memory test, the computer tells me the memory is fine, and a second later it BSOD before windows even loads.

The BSOD is "IRQL_NOT_LESS_OR_EQUAL or something like that. It resets too fast to read all of it.

Q6600 (oc'ed to 3.3ghz. It passed 8 hrs of small FFT's)
Crucial Ballistix 2gb ddr2 800mz
BFG 8800GTS
P35-DSL3

I read somewhere to reinstall the mobo drivers, so I'll do that as well....

I'm wondering if something is overheating? That might explain why it works again after waiting an hr. But my processor and GPU temps are good....

Yeah I've got the memory at 2.2v. I think it's BSOD'd at stock as well, but you are right. I should return everything to stock just to verify that the OC has nothing to do with it.

I think the error ID is 7026 (I'm at work, and I forgot to write it down). I'll do some googling....