it sounds like you might have some corrupt files there or your hard drive might have suffered from powering off whilst its active. If i was you i would make a backup or ask your distributor to send a back up disk set. Then connect the keyboard to your computer and run the disk check program. On XP you right click on the AUDYA drive and go to tools. But only do that after backing up.

Regarding the hard disk...never turn the Audya off when the hard drive LED is ON (any colour) or flashing.