ipod 5th RB version 3.15 panic no mount

[aloha]

model:ipod 5th
RB version:3.15

would anybody help to solve this  problem?

after unplugged ipod, always shows up this.

panic mount 0
pc:00071b7c sp:00100358
bt end

so always I restart, then I can use as usual RB.

when I unplugged ipod, from exploer, there was no problem on my PC.

whats happening.

too many MP3 tracks?