Oddly enough, I am currently dealing with a similar situation. I have been running at stock on every setting because I'm still held back by my graphics card the most. My sig rig is up to date if you want system info.
I seem to have it occur in waves. It will occur several times in a short period of time, then it goes away for a while just when I'm trying to troubleshoot. The only thing I have confirmed so far is that sleep mode has a greater than 50% chance of causing a blue screen.
I don't mean to hijack this thread. It's just odd that I'm having a similar problem and that as far as I can tell, the problems seem to lead back to memory...possibly... The only other indication I ever got seemed to imply i/o on the motherboard (i.e. one of the 'bridges) but i could never get anything beyond a vague implication that it could be motherboard related.
The blue screens go much further back but those are the two recent waves. My computer has then seemed fine since that last one on the 31st. I just need to go ahead and do the memtest and check the psu voltages. I have a Fluke DMM so I can check the psu. Anything in particular I should be looking for or just get a one time confirmation that voltages are good? And now that I have more proof that the next step is to check ram, I will deal with that tomorrow.