I have a HP Compaq nc6400 equipped with an intel T2500 CPU and a Radeon X1300.
When grub boots if I stay idle on the grub menu after a few seconds the fans would kick in. After less than 30 seconds the notebook would overheat and shutdown.
This does not happen at the POST screen, in the BIOS screen, in the boot device selection screen.
When I boot into the OS (Fedora or Windows XP), after 5-6 seconds what was malfunctioning eventually gets initialised and the fans speed lowers.
Once in the OS the notebook can be used 24/7 without any overheating problems even under heavy load.
Note: The same happens with Ubuntu 10.04. If I boot into memtestX86 (that stays in text mode) the notebook would continue overheating till shutdown happens.
I can reproduce this problem at every boot, but I do not know how to provide significant logs, since it happens before the OS actually starts.
Nevermind it's a hardware issue. The result of six months of useless discussions related to
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/524281 and other scheduler related nonsense.
My CPU is fried, thank you very much. The overheating is not related to GURB, since it happens with any text-based application.
Back to Windows now. It sucks but at least idle temperature is in the 48-55 degrees Celsius range instead of 69-73 since there is no idiotic load balancing code overheating and frying your CPU.