I bought a Lumia 920 one month ago.
Since first day I'm having problems with music player. When I click to play a song it takes several seconds to update screen, moreover hardware buttons doesn't do anything. After a few seconds mobile starts to work again, and everything seems well.
It happens with any application that play music (microsoft, nokia and mine), and with any music file. Same files where working perfectly on a Lumia 800.
I did a small search if somebody had similar problems, but I didn't find anybody (¿?).
As I said, it happens with all application that play music: nokia music, windows player, and one application that I developing. I click to play a song, music starts to sound, but mobile gets lock for a few seconds (around 30 seconds!). I tried to click back button, power button, ... doesn't matter mobile is complete lock, after this time, mobile starts to process all clicks (back, power button, ...)
I Attached a video ...