I have a macbook pro 2.33ghz running 10.5, which I've set up as the same system I use at work for convenience' sake. It's not an important use machine, but comes in handy to make sure anything I discover at home that's useful will also work during the day. In the last year I've installed CS3 and 5 on it and built up a decent copy of my work Mac. Yesterday afternoon at work I copied a few files to the MBP, closed it to sleep it, and came home. An hour after getting home I opened it up and it'd turned off (not so unusual, the battery isn't great on it), but it booted straight to a fresh install and first boot request for account creation. EVERYTHING I'd ever installed on it is gone. It's a fresh brand new install of 10.5. No mail, no apps, none of my files, all of it's disappeared - there's no evidence it was ever a used system. What's happened here and how can I stop it happening again? I've lost access to about two gig of files I'd like to have looked over this weekend.