I got a few tracks that can't complete syncing via the software, it says something like "blabla couldn't transfer" and then some error code. Anyone with the same issue?
I've had what sounds like the same message using the Windows Phone application for Mac. It seemed to happen when the song / album / artist name had 'illegal characters' - like '?' or '/'
Renaming the file or changing the metadata to get rid of the characters sorted it out.
Try importing from windows media player