Sorry if this has been answered elsewhere, but I searched and couldn't find any useful information. I have a 20 GB ipod that has been acting strange. The course of events goes like this: I begin by updating the ipod on my Mac, and everything is fine for awhile. All my songs, including the ones purchased from iTMS will play. After I've run it for awhile and the battery is low (though not out), I leave the ipod for awhile (a few days maybe) after turning it off. Then, I'll come back to it, hit the white button in the center (it won't turn on by pushing the play button) and attempt to play my music. Everything will play fine except for my iTMS songs. Those will flash the title onto the ipod screen for a moment and then skip to the next song. Nothing is done to the ipod during the few days it's inactive. The problem is fixed if I plug the ipod into my computer (subsequently updating it). What's going on here? Is this normal operation? Any help would be appreciated.