Thanks for the reply joe. I've checked fan/heatsink integration and it's well placed. I think the problem is the BIOS using 100% CPU speed, while windows only increases CPU speed when user or process demand so. I guess BIOS does not controls CPU speed and sets it to 100% all the time, which triggers fan speed to maximum, and getting the CPU hotter.
In windows I don't get these high temperatures, and fan is always on low speed (can't hear it most of the time). I only hear it when playing video games or using cpu intensive applications (basically when CPU gets more than 20% usage). This is an i7 2600.
I'm going to try to upgrade to 77 and post back results. I hope it solves my freezing issues. Remember that my computer freezes only when windows is restarting, I think exactly at the moment where windows signals computer to shut down itself (or reboot) so I don't think it has to do with overheating, because I use my computer all day (in a cold room, that is) with intensive video gaming and I can hear CPU (and also sometimes PSU) fan spinning hard, but temps stay in a normal range. That's why I think it's a problem with my current BIOS. It's the only (major) issue I've seen so far (appart from bios setup screen using 100% cpu speed), however after reinstalling 0072 a few days back I haven't suffered from any other freezes, I updated windows normally, it didn't freeze, so maybe it was a bad flash the first time around.
I think I'm going to pass (for now) upgrading my BIOS, until I get another freeze. Hopefully it won't happen again.
Thanks for your help.