It's the Master Playlist that I cannot get past. This is the first playlist it is sent when you Select Music/Playlists from the menu on the RR. This actual playlist file at the moment lists all the albums and is 825 lines long. There's no actual tracks in this list, just pointers to the album playlist files that contain the list of tracks and pointers to the actual music files, but I can't get that far. I select Playlist and it goes away for a second (so it's trying) and returns the error. The access log shows it tries to GET the URL 2 or 3 times then it gives up (and presumably then shows the error message).

I don't see how a list of 825 items should be a problem, especially when after the file is temporarily truncated the RR is quite happy with the full sized original.

How sensitive is it to funny characters, i.e. not regular ascii?