Could you try to uncheck/recheck "Available Offline"? See if that helps. If that doesn't help try doing a full reinstallation of the app, including removing your local cache/data files.
A log out and then back in again sometimes helps too
Please use the search feature before posting a problem/bug/idea. What's a Spotify Rock Star, and how do I become one? Using Spotify Since March 10th 2009 Twitter: @mechanimal82
