I have tried all the solutions mentioned in this thread, it's still not working. My mute button works and so does the volume roller but not the play/pause, stop, next or previous. Please help, I just got this keyboard today.
Update: I remapped the stop key to the spacebar, and it works... I remapped the spacebar to stop, and it doesn't work.. So it seems to be the software or the audio controlling thing, not the keys themselves. Not sure what to do.