I have a strange problem with my Droid 4: sometimes it stops playing sounds (or music, or ringtones), and I can't figure out if there's something in particular that triggers this. The only fix I could find is rebooting the phone. What could I try to diagnose the problem?
(I'm using a Verizon-branded Droid 4 with Cyanogenmod 10.1.3, but I had the problem on 10.1.2 too. If it's relevant, I had to install "Tobby's mod" to enable GSM - I'm in Europe)