This has happened twice now. Last week my iPod would skip over songs purchased on ITMS when on the Shuffle Song setting. It would display the song title briefly then move to the next song. I went to that album directly and it displayed and skipped every song on the album. I checked my Mac and everything played fine in iTunes. I re-synched the iPod and all was fine. Today I'm listening to the iPod and it's skipping purchased songs!! argh!