Hey all, I just received my first Mac last night, a white 24" iMac, and have spent the last day or so trying to get acclimated to it. I have to admit the transition has been a bit choppy, as I've been using Windows for so long, but I'll get there. It's a very cool machine. One question: While the computer is very quiet in general compared to my old PC, I do get an occasional, very soft "skritching" noise from the HDD as it's reading. It doesn't happen all the time and, like I said, it's very soft and not overly noticeable at all and the computer runs great. Is this normal?