Ok, so My ibook was virtually SILENT unless I had a cd in, for nearly a year, Now it makes this kind of whirring soft clicking sound, seems to be coming from the front left side of the ibook. Sometimes it is constant,sometimes it goes for about half an hour, shuts off for a bit and then goes back to it. Should I be worried about this? I know for a fact that it NEVER made this sound before. I don't know when my warranty expires, but I think it is pretty soon, should I be looking into sending it back?