I have what I consider to be a large iTunes Library, ~38 days of music. Worse? I'm a stickler for tags to be correct. Worse still? I'm SUPER lazy, and like things to be done for me as automatically as possible.
Some time ago I used a piece of software that had a particularly nasty bug which corrupted the tags on all of my songs with non-latin characters. I've since updated and re-run the same piece of software, and as I play songs previously corrupted, I see their tags update and become correct and intact again. However, after some amount of time, it seems that the tags revert back to their corrupted state.
This seems to manifest itself in other songs where no corruption has occurred, but the comments and some other custom keys I encode into the files disappear, or revert, as well.
I think this is because there is the tag data in the files themselves, but also in the iTunes Library files (itdb, itl, and xml files). I think that the data in those files are taking precedence, or failing some sync, or in general just failing in mysterious ways causing the above stated issues to occur.
What is the best procedure for updating a large chunk of tags in my library, and ensuring iTunes sees them, respects them, and will not continue to muck with them any further?