Norton Internet Security- Firewall blocking my Sonos system on new Windows 8 PC.

I recently installed NIS (version 21.7.0.11) on my new Windows 8 machine. After I installed it I can no longer access my music library for my Sonos system. I have given the Sonos desktop controller application full access but still get "Cannot access.." messages when I try to play or Index my library.  If I turn the Firewall off, everything works fine.  Any suggestions on what I am missing in the set-up for NIS?

Thanks.