GA-965P-S3 sudden not post requiring CMOS clearing... thoughts needed

GA-965P-S3 (or any) suddenly not posting requiring CMOS clearing... thoughts needed

Hello running an 965p-s3 mobo with a e6600, DDR2-800 and a en8800 GTS 640mb vid.


Background---

I had it OCed to 2.88 with 320FSB and 800 for the ram (2.5 multiplier, memory is DDR2-800) so nothing major. Only overvolt is the mem for +.2
Running XP

The videocard I was able to overclock 30% for both the GPU and memory (very happy) but that's done through ATI tools and during gaming only.

Everything was very stable, ran Crysis for hours no problems.


Problem ---

while playing around with Vista (on another hard drive which I swapped to using boot order in BIOS.. didn't want to bugger around with dual boot) I had some problems shutting down ending up with a hard power off (power button) to get it shut down.

But then one time I tried to fire it up I got nothing, no post, no signal to the monitor, the vid card fan running flat out (usually quiet) etc.

So after a little freakout, I pulled the power cord and popped the battery for a CMOS clearance. PC fired up fine after that.


Question -
Any ideas what happened here? I'm used to things getting unstable etc when you push the limits, but not something going from working fine to totally dead. The only CMOS changes I was doing (after the new HD install) was changing boot order on the drives. Can CMOS get corrupted from just a save, or Vista has even more power to blow yoru PC up?

Thanks for any thoughts, this problem is a new one to me.

Tonto.

something in the bios might have gotten fubar'd that it required a deep clear...