Just OC'ed my Q6600 yesterday and had everything stable and working fine. I opened CPU-Z and noticed my multiplier was jumping between 6 and 9. I have speedstep disbaled. When I was in game (COD4), everything worked fine. There was a different option in my BIOS that appeared to have some power saving/throttling function but I left that on. Cant remember what it was. Maybe that is it? Does it really matter as long as its going to 9 while I am gaming? I OC'ed it to 3.0 with the 9 multiplier. Didnt seem to like the 8 multiplier. Was trying to do that to get closer to the speed of my 800 RAM.
In response the BIOS question, I dont know that I have ever updated my BIOS. I have all the latest chipset drivers and video card drivers and all that. Don't think I ever really did anything solely with the BIOS...or did I with the chipset driver?
The BIOS is the main part of the system. It tells your computer what it can support and a lot more. In order to update your BIOS you need to go to the mobb makers site and look up your specific model and download the latest BIOS.
Most of the newer mobos do support flashing the BIOS via a USB Thumb drive. If I were you I would consult your mobos manual for BIOS updating to see how you can do it.