Sorry to sound like a n00b, but I warn you that I've been having weird things happen with my Fedora install (Dbus org.freedesktop.Notifications.service file wasn't even there). Fedora is functioning, but it's taking a lot of work just to get certain things working.
Anyways, on to the problem. When I click the Off -> On icon on the Gnome Extensions website for your extension, it pops up the usual Gnome3 dialog asking, "Do you want to download and install the extension?" I click "Install", and the dialog disappears as normal, but the icon never shows up in the notification bar, the extension doesn't show in the Volume icon (as per the Github readme), and the extension doesn't show up in the extension list on Advanced Settings (gnome-tweak-tool, not sure if the extension is supposed to show there). The extension shows as installed on the Gnome Extensions website however.
I am using Exaile. I have also tried running Banshee, and still nothing.
Is there logs somewhere? Or a way for me to manually install? Wait....ting! I forgot about simply compiling your extension. xD I'll try that, and keep you posted.
Oh, I'm on Fedora 16, just some extra info. :)
Edit: Figured out that Banshee didn't have the MPRIS framework extension loaded. Your extension works now.
I had MPRIS loaded on Exaile, but I found out it still doesn't have MPRIS2 support. :\
Either you're going to add MPRIS 1 support, or Exaile needs to update...this sucks.... oh well. lol.
Closed.