I don't have much to offer you, but I've been using it since the day I got my N3 and it works fine for me. Try clearing data, uninstalling/reinstalling etc. If you're rooted try clearing the cache's. Something you have is interfering with it.
Also bring up volume's in the sound menu and make sure the media isn't just turned down.
Wife walks in...
Wife: Hey what are you doing?
me: Nada, phones finally rootable.