podcasts suddenly sound like a chipmunks recording

A couple of weeks ago, I synced my iPod and got ready to go on a trip. My podcasts suddenly sounded like a chipmunks recording -- very fast-- like I was playing an old-fashioned record at the wrong speed, or was listening to a video while fast-forwarding it. I checked upgrades, and seem to have the most recent version of iTunes. Prior to this, have never had this problem. Help!