I am not sure what is happening with my hard drive, somewhat odd. Laptop Specs. Mac Book Pro (10.4) 2.2Ghz 2GB RAM 667 MHz over a period of time my free space (say about 20 GB) will slowly disappear, down to about 3-5GB. Then in a vain attempt to fix the situation I delete a few music/ video files or run cleanup programs. None of these seem to have any impact, any room I clear up will disappear as well. Then all of a sudden, after one fateful computer shutdown it will all come back and I will have even more memory then before. Why is this? It is very frustrating since my computer becomes horribly slow when at the low end of this memory cycle. I wanted to assume it was somehow the auto defrag of the mac somehow but feel this cant be the case since my memory only comes back after it turns off, and 15-20 GB returning for no apparent reason is alot of space. Also I doubt it is a virus as I have an upto date Norton Anitvirus in steady operation. Any insight would be appreciated.