My trusty PowerBook is being finicky with all the disks I try to put into it. It will draw them in, groan like it's about to spin up, pause, then groan some more. I hear it spin up a tiny bit, but not to the rate it usually does. The fact that it's spinning at all makes me think it's a read head/lens dirty problem, but I want to make sure before I blow money on a cleaner which accomplishes nothing. Thanks!