When I said that the 1.0, stable branch was going to get only crash fixes, it didn't occur to me that the program might stop working even if it didn't change. Well, along came Gnome 3.0 and a Discogs API change and now you can't easily close a window with the mouse and you no longer can query Discogs.
These issues got fixed in the unstable branch. (Well, I guess "fixed" is a strong word, as I still don't like how the program looks on Gnome 3, but at least I can use the mouse to navigate.) The fixes have been backported to 1.0.09, so with this change it is now possible again to query Discogs in the stable branch.