I've just been sitting here using my iBook, listening to music, email, internet and the fan is just cranking, you can hear it, its going like if I were working on a big movie project. Anyone know why. yes the hard drive is hot and so is .... ventalation? could that be it. let me see if I can prop it up a bit and get more air under it. Is this a problem if the fan comes on like this constatnly?