Portions of purchases not authorized to play

I have recently purchased 3 albums on iTunes. I have noticed portions of that music will not play on my laptop, nor will it allow me to download those tracks onto my music player. When I attempt to play these tracks i get a message to that says my PC must be authorized, so authorize it and nothing happens other than I recieve a message stating "this device is already authorized. Yet all the track show on the screen bit I just cant do anything about it.