I dunno when it happens, but every single song I have in my collection is doubled up. It's done the same thing on my iPod. It's not just doubling up on the playlist, it's actually creating doubles of the .mp3 files. I had a look at the encoding options and did a search for and aac files it might have been converting them too, but no, both sets fo files are .mp3s, the only difference betweent he files is how they're named. THe priginals have their normal names, but the copies have either swapped the artist and song title or they just have "1" or "2" tacked on the end of the file name.
Please help, I have 92 gig of music which should only be 46.