Paul,
I found another issue. I had a song with the title:
Pavane Pour Une Infante Defunte\
The trailing backslash was causing the 503 error when connecting to MusicBrainz. The only error reported on the console was “MiniProcess 0 having problems connecting to MusicBrainz Service, may be down or just busy”…
Removing the trailing slash got rid of the problem. I don’t know if it is improper escaping of characters in Jaikoz or an issue with MusicBrainz.
-jim