Hi, I just autofilled a lot of music from many CDs into my iTunes library and chose "autofill" to the music in iTunes over to my iShuffle. If I add additional songs to my iTunes library from different CDs, etc. and then choose autofill again to add the new ones, will it duplicate the ones that are already there? or just the new songs I've added which is what I want. I don't want the songs today synced twice onto the iPod! Thanks T.