iTunes 10.1.2 won't play songs

I just downloaded the iTunes update and it seems it's got a big problem. I can press play and the button will change to pause and the album artwork and title at the top change (i.e., it knows I pressed play) but nothing happens. The time bar won't advance and there is no music. Has anyone else seen this or know of a fix?

After some Google-fu the only solution I could find was rebooting. That worked for me this time, but does anyone know the larger issue?