No Items to display

[Petrarch]

I have installed Mezzmo, have got it working, loaded it with media and am able to see it on my Sony TV. I can also see the various media types (Album Artists, All Music Files etc.), but when I try to select a media type, I am always told by the TV that there are no items to display. In Mezzmo, I can see the media. UPNP is turned off, the Mezzmo port is opened on the router. The attempt to read the media is not registered under Media Devices.

What to do?