Hi there, Weird things started happening on our iMac a few weeks ago. all of our iCal info went missing, favorites in Safari went missing, desktop wallpaper and screensavers were changed, icons with iPhoto library just appeared on our desktop - very odd things. What could have caused this? We've taken it in for service but I am curious to how this happened? A friend mentioned he thought it might be a 'corruption in user'. How does that happen? (if it is the case) Thanks!