FYI....1.51 error . . . but...

Just had little trouble updating mpc after my 5h session. After quiting all the PT/Logic/NI applications I downloaded new OS X updater and tried to update. It crashed, while erasing the old OS, but right after restarting my PowerBook, the update went smoothly.

So, restart your comp and save yourself from troubles (1.45 needed in case)

hello,
It is always wise to keep backups of your current OS, And olders ones too.