I stumbled on a problem which I haven't had a chance to reproduce yet, but which I think relates to either the Firefly server (I am running svn-1025 on Windows) or the RSP protocol handling in the Soundbridge, because I haven't had the problem when using UPNP (with either Twonkyvision or WMC).
Anyway, here are the steps:
1. Play back from Firefly library (specifically RSP protocol output).
2. Drill down through artist/album and play an entire album.
3. Press Pause on the remote (would have been about 30 seconds from the end of the track, but maybe doesn't matter).
4. Leave it paused for about 5 minutes.
After this what I saw happen is that playback resumes normally for about 30 seconds (I'm guessing that is the length of the buffer in the Soundbridge). THEN that track stops playback suddenly, and the Soundbridge attempts to play the next track on the album. This fails, and all subsequent playback attempts and attempts to navigate the library on the Soundbridge fail.
Choosing any media server also fails, even though the list of media servers is still correctly shown.
The Soundbridge has to be rebooted then everything is fine again, and dozens (hundreds) of tracks can be played from Firefly with no recurrence of the problem.
So, it appears to be something to do with using Pause when playing via RSP (I've never had such a problem using Pause with UPNP on the Soundbridge), but I'm not sure how reproduceable it is or what other factors might be included (ie whether it has to be a WMA file - as mine was - or pausing at just the right/wrong distance from the end of the current file, or what). Can anyone else reproduce this (or not) following the steps above?