First post in a Forum.... Been fixin and buildin my own for years. Here goes...
When ever I change any settings from stock to OC and reboot or cold start my computer starts for about 3-4 seconds then reboots and most of the time posts on up and runs normal. Every now and then it will reboot a 3rd time but then goes back to stock settings and continues posting. I never get a bsod (bios F2), all power saving options disabled in bios, PCI-E at 100, memory timings loose. Once it posts it runs perfectly. I tried all kinds of different memory timings, goosed the cpu vid to 1.3, raised mch by .1 and fsb volts by .1 in an effort to find out why this posting phenomenon occurs. No matter what I have tried, when I OC this posting regimen occurs. I play Supreme Commander Forged alliance alot and no issues the game just rocks with all the goodies at max and 60fps with fraps. Any smoking grey matter out there with a clue?

I usually don't run the "stress tests" due to time involved. I have run memtest to completion with no errors. However the problem I am experiencing is only occuring when I do a cold start. I have everything on power surge protection and turn off everything each night and then switch off the surge protectors isolating my system from power completely. In the morning or first start I power on the surge strip wait a few seconds and then hit the power button. It starts up normal, meaning the fans and lights and hardrives start up but just before bios posts (about 3-4 seconds) it reboots like I had hit the reset button manually, and then powers on up at whatever FSB I had selected. I have gone up to 3.2ghz where I am now. I have never BSOD'd in Vista 64 or XP. This seems to be isolated to the mb post up routine. Every now and then it will reboot a 3rd time and if that happens my bios resets itself to stock. If I hit delete and then go back and change it all back to my oc parameters and reboot its fine????? Something in the bios doesn't like what it sees on cold startups. I have my setup go to sleep after 30 minutes, and when I come back and hit the power button it comes to life without any rebooting. I did rma one stick of memory a month ago but the problem still remained with the new stick. Does removing the psu from power have anything to do with this? It never happens unless I have oc'd the bios. Perplexing?

Do you have a Gigabyte motherboard by any chance?

Yep, its a GA-X48-DS4 with F2 bios. Is this a Gigabyte anomaly? I have had no other problems but the occasional first post reboot and an extremely rare 3rd boot that resets bios to stock. I have absolutley no problems once I boot into Vista64, or XPpro or Windows 7. I play Supreme Commander, and Sins of Solar Empire maxed out with no problems.

It is Gigabyte thing yes , mine did it when i first got my cpu to 3.4 gig , it jsut went away on its own?? lots of gigabyte owner/overclockers seem to suffer from it , it doesnt seem to do any harm