All of a sudden, all of my keychains were gone. Then the next time I restarted iCal, all my calendars were gone. Then the next time I restarted iPhoto, all my photos were gone. And so on with my music when I restarted iTunes, then my address book was deleted from Entourage. Also, all my bookmarks from Safari were undone. Finally, after restarting from installing the new iTunes, all my saved documents were erased and all my dock settings were undone. I have an iBook G4 that is about a year old. Any ideas on what is wrong?