Problem :
Going through my collection via Jaikoz, I have many duplicates for one simple reason : m4a vs mp3.
When receiving or creating files then using Jaikoz on them to get album art and lyrics as well as all the other info, I normally rely on Jaikoz to throw up the error it receives from the file system but if the files only differ by extension, I receive no error and effectively have just created a duplicate.
Proposal : Since most people using Jaikoz probably have sane masking procedures and store their files in folders named on an album, i think it should be computationally trivial to look in the folder Jaikoz is about to save the file, and look to see if there is any file that already exists differing only by extension.
(Alternative - more difficult) : Or is able to look and see if any file in THAT folder (not across entire collection) has same MusicIP, MBID, or combination thereof.
(Alternative #2 - even more pie-in-sky) Jaikoz evolves from tagger to music manager and thus stores all info about collection in database. Since it already knows about the MusicID and MBID, it knows if you are about to store a duplicate, no matter where in folder structure.