Found what I believe to be a little bug last night in Ver 9.0077.
I imported media from my music directory (mp3s only). In that directory there where also 5 .m3u playlists that I had made.
When the import was complete, I was surprised to find a number of Albums that were apparently incomplete, which I new not to be the case. Upon further investigation, I noticed that MJ had added a second song in the database for the song as it appeared on the playlist.
So, I had, let's say Sheryl Crows latest album. One of the songs from that album was in a playlist. Upon looking at the Album, it showed 12 tracks instead of the 11 it should have (not sure of the exact numbers, this is just for illustration). One track was duplicated with a messed up tag, the Title was the full file name of the song (Artist - Album - Track# - Title).
Hope that makes sense. You should be able to repeat it by making a playlist, then importing songs into a clean library. Make sure that the songs you import are part of that playlist.
Adam