There you got me, i am not up on laptops as much. What does you temp read in bios. That might tell i you if the fan although running, might not be runnning the way it is supposed to. IE, your cpu is running hot. luck.
dfi nfII ultr infinity/asus p4s800
amd 2500xp m/p4 2.6
ati 9600/ati 9600 pro
512mb pc3200/512mb pc3200