First let me thank you for writing this plugin jhowell. I think it will be very useful.
I have run into a small poblem and don't know if it's something I'm doing wrong or an error in the plugin.
I installed the plugin, added it to the menu bar and everything worked fine. I then added the plugin to the favourites menu button and that worked also, until I removed the plugin from the menu bar.
I've tried restarting calibre as well as removing and replacing from the favourites menu. Nothing seems to make it work unless it's also on the menu bar, which I don't normally use.
Has anyone else successfully added the plugin to just the favourites menu?