The issue I am having is not related to the side buttons (ring/vibrate/silent). I have an iPhone 4S, I am running iOS 7 beta 3. The phone has been working great up until yesterday. I plugged my phone into my car and a box came up that said "Volume Mute" with the speaker icon and a slash in it. I have no audio from the phone ear piece, speakerphone, headphones, nor does it work through the cable to my car or any other device. I can not find a way to "unmute" my phone. I have tried apps, preinstalled apps, nothing seems to work. Any time I plug in the cable in my car it says "Audio Mute" every time. Any help would be greatly appreciated.