Having the odd issue with OMP lately.
It's a bit of a vague bug report, as I haven't had time to try and pin it down.
It seems to be related to removing the headset, I'll be listening to music and then remove the headset (this pauses the track). I'll then do other things maybe get a phone call (so OMP gets minimized). On reinserting the headset the music will sometimes not play automatically and even if you poke, play nothing happens.
The now playing screen appears to get stuck. The track title is still displayed in the menu bar instead of "Now Playing". The only way to get the music playing again is to close OMP, or start a new playing session.