iPod Touch 5g unable to sync with iTunes

Hi,

My fairly new iPod touch 5g has synced perfectly fine with iTunes 11 before, I have set it to sync one certain playlist and until today it worked fine. Now when I try to sync, it does the usual routine but does not add any newly added music to my ipod library. When I view the music on the iPod via iTunes, it shows the new songs greyed out with a little dotted circle next to them, I assume this means it isn't synced. Pressing sync doesn't change anything.

I've tried various fixes like holding down the home and on/off button down, plugging it in, and waiting ten minutes, which did nothing.

The sync just seems to think there's no new songs to add when there is...

What should I do?