I first noticed the problem that I have now when I was downloading a fairly large file on safari. The finder alerted me that I was low on disk space, and sure enough, when I checked, I had about 100 megs left. I know before i downloaded the file I had about 10 gigs free and the file was only 1GB. I moved some extra things that I didn't need onto my external hd and off of my internal one. After that, it said that I had about 3.5 gigs free on my internal HD.That still wasn't right. I used carbon copy cloner to copy my entire internal HD to the backup partition on my external HD. I erased the backup partition before I did this. I checked the backup partition and it said that it had 11 GB free. The backup partition and my internal HD are both 20GB.. If I select all of the items on my hd and select Get Info, it says that they take up 4.65GB but it says that I have 3.54GB free on the window. It says the came thing in the activity viewer. I restarted, repaired permissions, and reset the PRAM. Argh! Why doesn't it work? Edit: Added pictures. The second 2 are from the activity monitor.