Ok so my 2009 MacBook Pro decided it wouldn't boot. I thought I had a corrupt hard disk or maybe the file system had gone haywire. However when i boot via firewire everything is just fine. I can verify the disk booting from CD but cannot repair it because I cannot unmount the hard disk. (I've tested this with two hard disks). Everything that I used to be able to do internally I can only do via firewire. The hard disks boot fine via firewire The hard disks repair permissions fine via firewire The hard disks unmount themselves fine via firewire The hard disks erase fine via firewire The hard disks install OS X via firewire And just as a special note, the hard disk is visible to the laptop when hooked up internally, it can read the information just fine and can "verify" but not "repair" Any thoughts?