2 day old build - everything new. getting blue screens of death at random. passed 1 round of memtest86 3.4 boot cd.
(1st day): windows installed easily, windows updated, drivers installed, not long after i start getting comfortable with my new system boom BSOD! got multiple different errors at different times - here is a list of different blue screens i got:
irql_not_less_than_equal - this one happened when i pushed the power button.
(2nd day): format + reinstalled vista64 no problem. instead of the supplied driver cd i downloaded everything individually from asus this time. windows updated. started up microsoft mail and half way through the new mail download BOOM.. driver_irql_not_less_than_equal
all stock, no OC. I just ran memtest for 6 hours without error. as soon as i reboot into windows i open iexplorer and it crashes with bsod "pfn_list_corrupt". i reboot and windows starts with "ati catalyst couldn't load". i don't know if i should lean towards ram or gpu. i'll try running one stick of ram. i have no replacement parts, my old box died and is 8 years old so whatever is wrong i hope i get it replaced soon (if it's hardware). i only have a few days warranty left on these parts with newegg.
I had same thing with same proc/mobo w/ BIOS 1201. If u google around u'll find that BIOS 0803 is what works best with Q9550 or from what I read any Q9xxx processor. Anyways - worked for me and this BIOS downgrade stuff is highly annoying so I figured I'd pass it along