I just had this problem. Try the following steps.
1. Reinstall your iTunes, Download the latest version.
2. If you download your music like i do sometimes you get a bad torrent and the mp3's in that torrent do not copy to iTunes, download another torrent.
3. Restart your computer (I'm sure you've done this)
4. Restore your iPod.
5. Delete the iPod drivers.
Anything else i can think of is just keep trying to sync it, open it and close it. Plug your iPod into a different USB port. Make sure the drivers download again.
Hope this helped. (: