What's probably really happening is that the audio buffer is falling behind then it starts turning off synchronization in order to give the emulator time to fill the buffer back up. This is the desired behavior, it helps prevent audio skips if the speed falls behind for just a bit. But for you it's consistently running at 95% which is well below 100%, so it falls too far behind. The frame regulation usually works a lot better than that for me, sticking very close to 100%. Do you have any idea if something could be interfering with the display refresh rate or audio sample rate (like a specified .asoundrc)?