A tip for those getting errors like "The shared music library "iPod" is not accessible for an unknown reason. (-3260)
Check that any firewall softawre running on either the shared computer or this computer has been set to allow communication on port [2000, and others]."

Change the port on which MusicPublisher runs. If you have iTunes running on the maching with sharing active then you can not share from both iTunes and MusicPublisher on the same port. This is one of the very few things documented, not sure how people miss it. (It is a simple enough app that documentation is largely superfluous though.)

I find the app very useful in that I have 2 iTunes libraries that I use on my PB with regularity (One on my powerBook hard drive with only about 1000 songs, one on a FW drive with ~9000) This allows me to run the local library all the time and use MusicPublisher to "share" my firewire library with myself. This is easier for me then switching back an forth between the two libraries.