I have a g4 single processor 867 that I just got it and I'm really getting worried about the fan in it as it's making wierd noises. It's going uurr urrr urr as if it's kinda grunting. I think it's because it's dirty inside since I have to keep the unit on the floor in my dorm room because the desks they provide us w/ just aren't big enough to put it on the desk along w/ the monitor. I looked inside it, but I couldn't see any way to get to the fan. Does anyone think my fan is in serious trouble? Should I look into getting it cleaned somehow?