So I was using my laptop tonight, when I had my head near it, and I heard this slight noise. It almost sounded like a super-quiet sizzling noise, like a very small fly trying to fly. I know its not from the DC-in board, because the laptop charges fine (sometimes the DC in board makes a buzzing noise if it is not working properly, mine is thank goodness), it seems to come from the left-hand side of the laptop. Its not like a hard drive clicking, I've ruled out the HD. The noise is coming from farther up. Is it part of the MB? Processor maybe? When your in a quiet room by yourself, you can hear it barely from an average distance away (maybe a foot or two). Anyway, its kind of annoying. What is it? Is it normal? EDIT: I have another iBook MB, and I turned it on, but I don't hear the same noise at all, but that doesn't really mean anything.