When playing games, I get an occasional stutter and then the sound will start going very slowly. It's all crackly and laggy. It's happened to me on FIFA14 and Asphalt 8. Don't really play any other games so can't really tell if it's just isolated to these games. Anyone else have this? It's only come apparent with 8.1. Oh, I'm using a Lumia 820 is case you were wondering.