I've also noticed another issue (I'll file a bug tonight) that happens with both my DBus backend and the Rhythmbox one. Suppose you have a set of containers under root that are
Album
Artist
Genre
and you then navigate Artist->Beatles->Abbey Road-> (list of tracks)
when you navigate back to the root container it now shows
Abbey Road
Album
Artist
(ie it has put the lowest level container into root - in alphabetical order - and discarded "Genre", presumably because it only expects three in the list)
Anyone else getting this? I'm using the official Ubuntu 14.04 versions of Rygel and Rhythmbox
James