Seeing this tonight brought me back to the days I tried to do all my multimedia from a Nokia. As anyone can tell you updating the library is an all to common occurance with Nokia previously concealed by Apple.
Looks like those days are toast.
Nokia shares the “fun” with Apple
I've seen that screen just the once, I think it was after an interrupted sync.
Happened a few times for me … Think it has something to do with genius. Though that should all be handled on the computer side since it knows in advance what's going to sync over.