I’ve figured out why I’m missing so many files. Firefly seems to be struggling to map files from the iTunes XML to the file system if the file name or path has an accented character. An accent in the iTunes song name or details isn’t a problem, just if it’s in the file path.
Here’s an example of something that doesn’t make it through (iTunes string then filename):
\HoraceMultimediaiTunesiTunes MusicBjörkDebutViolently Happy.m4a
The same problem occurs whether the extended character is in the path or the filename.
I’m surprised this isn’t being flagged in the logfile, even with level 9 debug.