Files are disappearing from the computer repeatedly
starting last week, randomly all the files will be gone. all applications installed will still be there, but every file the user has ever created will disappear completely. We have Crashplan running backup constantly, so we are able to restore the files, but a few days later, all the files will be gone again and we have to restore again. by gone I mean completely gone. search for any file and it doesn't exist. eerything on the desktop or in any folders (the folders are gone too.) all the programs will be there and be unable to find any recent saves.
What is causing this and how do I fix it? This is a computer at the office with a single user, no one is logging in as a guest. I think it's running snow leopard - unsure of the version.
iMac