losing memory

what programs are you using?

Just curious what sort of software you might be using... and does the harddrive space still appear to be gone after a restart? If you are using photoshop, or anyother pro graphic program- it is very likely the scratch disk is being used up... sorry if you know all about this, but just incase- photoshop among others uses the harddrive to keep itself running, and when holding large images in the clipboard, it will take up harddrive space to sort of temp store the info.. almost like virtual ram..- anyways if working on big files in the program for over an hour, your harddrive will quickly dwindle.. and from my experience, even when quiting PS it still appears to be gone.. yet when you restart the comp- presto its back. If you have multiple harddrives, its always best to set an external HD as the scratch disk.. as back in my ibook with a 10gb harddrive days- i crashed the computer and all of my dock/mail settings multiple times from allowing photoshop to essentially eat ALL of my harddrive - no prefs could be saved.. and lost their settings- it was SOOOO anoying... so always make sure you have a couple gigs available on the scratch disk being used (primarily when its the startup disk)- and if you are not using any of those pro apps... then i got nothing.. hope that helps