[Ipod Shuffle] Sync does not work!

[doesitmatter]

Hi,

I just bought a new ipod shuffle and the syncing is not working for me at all.

I paid close attention to this guide: http://support.spotify.com/us/learn-more/faq/#!/article/How-to-sync-iPod-with-Spotify

but once I've erased the ipod and checked the "manually choose playlist to sync" checkbox and selecected my local (i.e. downloaded) files nothing is happening. 

EDIT: Nothing is not entirely true... I see the "syncing symbole" for a second or so but there are no files which get copied to the ipod.

Btw: "Enable disk use" is enabled in iTunes.

What am I missing here? Is there some magic button to click?

Thanks