Hello. I have an iMac with 38 GB Hard Disk.I have Mac Leopard 10.5.8 installed. The available free space( when I click on Hard Disk symbol and then information) shows 11.5 GB and 26.5 GB used space. When I manually add up what I have on all my files it comes to only 21.5 GB Where is the other 5 GB? Does the System use 5GB of Free place as reserve or memory? Thanks for help.