A bizarre thing happened the other day... I was using my PB G4 1Ghz, when it suddenly froze. I pressed the reset button but while rebooting, the screen remained blank (black). I pressed the reset button again, and it booted up ok, but the desktop appeared to have reset itself. The dock contained items like .Mac and the address book, which I do not normally keep there, and other I do use, like Limewire, Photoshop and Elements were gone. In a similar way, all the folders had white backgrounds and scattered icons, unlike the aqua blue and snap to grid I normally use. While fortunately no data appears to be missing, iPhoto will now not function. The program runs but when loading photos, bombs out. The pictures are still there in the iPhoto library, but some will now not open in preview, giving the error 'the file may be corrupt'. Although it appears I have got away without much serious damage, I am concerned as to why this would happen, and what I can do to prevent this happening in the future. I regularly repair the disk permissions, allow Panther to recover the vault space, and keep the drive relatively free of heavy loads. If anyone could suggest anything I would be grateful.