Err, I am not sure I understand. Adding 'refs' and 'FID' column everywhere will make it possible to see both how many times a particular tune file is referenced, and to positivaly identify it. So, if in 'All Tracks' view you see two instances of a particular song, you can be certain that they are indeed different files on empeg (with names same as FIDs). Of course, it will not tell you why are there two copies and are they indeed same, or, as you say, differ in encoding or something. A look at details popup could shed some light, but not necessarily. So, if you see that one of them is referenced twice, and the other not once, it might either mean that you may remove the unreferenced one, or that you actually intended to reference each one once (for some reason). You may have to listen to them (start them from emplode) in order to determine whether one should go

BTW, I am in the middle of pruning duplicates from my empeg: it's amazing how many of them I managed to upload. CVS listing and hex calculator are invaluable in this endeavour.