If you get into a predator encounter just as the Salt Mines transition into the pre-Bear phase, you're stuck in a black screen until you die. Once that happens, the transitional wipes stay on your screen when you return to the pixel lobby and persist until you return to the main menu.
The music volume option when tweaked in the pixel lobby has no effect on the volume when carried over to training mode or a fight.
...and DxDiag just in case. Don't worry, the frame drops there are my recording device