I lose about 1gb of disc space while I am online or doing whatever on my ibook g4 (leopard). I can't get it back until I restart my computer. I have a feeling that this is something to do with virtual memory, but am not sure. I use both Safari and Firefox (firefox seems to be a lot slower so I am trying safari). I have recently run Onyx and cleaned up everything, I think at least. Does anyone have any idea?? Thanks!