My USB drive that I took out my MacBook will no long boot. It's bootable but when it gets to a certain point the computer just shuts off. I booted to the HD in the computer to try to repair the disk and this is what I got. Any ideas? I just want to boot to the disk so I can make a quick backup of my address book. For the record I took to the old disk out put a new HD in my MacBook and installed a fresh copy of Leopard. I was able to boot the old OS via USB and now I can't.