recently I did a deauthorize all computers on my itunes account so I could bump off an old mac that couldn't connect to the internet. So I authorized my computer for my account to play a few old songs that I had bought before the stop of drm. I just bought an album on my ipod touch on the same account. I hooked my ipod up to my computer and clicked sync. It started transfering the album, then it popped up saying this computer is not authorized to play this music, authorize? I typed in my password and it transfered them and now I can play them. There are now two purchased playlists, one called purchased, and one called purchased on ipod. what does this mean?