I have (had) a 24" iMac, which I purchased on Christmas Eve this past year. I love it, but it had a tendency to make all sorts of nasty noises. This was mostly a clicking that the HDD made for about 5 minutes on startup. I ended up backing up my iMac and the shop where I bought it exchanged it for a new one without question, so it's no longer an issue for me. But I've read that a clicking HDD is not uncommon on the Mac and I was wondering if anyone can tell me if it's really that serious an issue? The store employees where I bought it all said that it was an impending HDD failure, although I've heard that isn't always the case. Any thoughts on this?