I've had my iPod for just over a week. I've synched to iTunes a few times. Each time I do so I get a warning that a specific song could not be synched because it's not compatble with playing on the iPod. Can't remember the exact wording. I've deleted the listed song but the next time I synch it gives me a different song that's not compatable. So a couple of questions: What types of files would play in iTunes but not the iPod? I thought all of my files were MP3s. Is there a way of easily finding out (within iTunes) which files are not compatable so I can delete them all? Right now I have to wait until each synch to find out which song is not gonna synch to the iPod.