Asus p5n32e-sli wierd bios problem

Hey everyone, I don't think someone ever experienced something like this, so I could really use some help  

I had this Asus p5n32e-sli board for a year and a half and it was working just fine (except the poor OC - never made it over 2.9 with Thermaltake V1 cooler).

So I updated the BIOS to 1801 and all was good for a while, until I got a new i7 rig. So I figured since I have a new toy for OC, I'd got easy on the ol' chap and loaded the non-OC profile. And THAN...

Vista x64 freezes 10 sec after loading no matter what.
Occasional BSOD with "A clock interrupt was not received on a secondary processor within" error.

Even worse - when I reverted to OC profile 2 which had it running at 2.9, it works flawlessly  

I loaded default settings, set up my BIOS from scratch (no OC) - same thing again
Switched ram from 1 and 3 to 2 and 4 slots - the same (2x2 Gb Kingston Value DDR2 @ 800, 1.8V default)
Disconnected USB and non-essential devices - no luck
Tried enabling/disabling Speed Step, C1, etc. for 2 hours - nothing

All voltages are on auto, OC is Auto (disabled) and it still freezes, while OC-ed on 2.9 works without problems  

Err.... Any ideas?