My hard drive, about a month ago, started to make beeping, squeaking and clicking sounds. First it was every 20 minutes or so, just a single squeak. Then it got more and more frequent to the point where every 5 seconds it would do this. However, there were no performance issues, and recently it has stopped making noise. Anyone have a reasonable explanation of this? Also, I got an iMac G5 2.0 GHz.