did you rescan your music collection? maybe the path information in your song db isn’t correct.
try a rescan through the webinterface 🙂
I got it working again, but just of curiosity, to do a rescan do you meen to start the background scanner? I tryed that but it did not fixed my problem, I had to change my music folder, reboot, and then change back to my original music folder and reboot again. This ofcource makes me wonder, when I add music, do I need to do this again? If a rescan was not to start the background scanner, how do you do a rescan then?