Is there a quick way to just turn off the audio system? Like an off button? It seems like it is always on and the only way to get it from playing is to turn the sound all the way down. But then it seems if you are listening to slacker, for example, it keeps on communicating with slacker. Or if listening to FM, it keeps telling me what's playing on the station I don't want to hear anymore. It's also a pain to turn the volume all the way down then have to turn it back to your desired listening volume. I'd rather just have an off button and then have all the displays say "Media Off". Sorry if this is a dumb question and I've just missed something very basic!