Been noodling around with the problem this evening and to elaborate but possibly mystify further, I found that the aiff files are showing up on firefly on itunes, but they are right down the bottom of the list, missing all their tags bar name & time (which is why I missed them before – I was searching under the artists’ names for them.) There’s no album/artist/genre information etc. They do also show up on the roku but again just with the song/name title – they don’t show up under the artist/album name.
This is pretty weird given that they appear in itunes with all the accompanying information. Seems as if somewhere down the line the metadata has gone awol which is why they end up at the bottom of the server essentially unclassified…