Out of curiosity, what was it doing in the minute or two while the front panel said "Building music databases" if it wasn't, well, building the music databases?

Good question. I obviously didn't read the original message properly. No, it's not mounting the drives read-write. The only time that the player mounts the drives read-write is when emplode/emptool tells it to. This is why you have to do a full sync in order to make it save the rebuilt databases.

Hmmm...