I was editing a project in FCP using headphones (klisph s4i) and i wanted to show the client the edit. When I unplugged my headphones I didn't get audio. I tried putting the volume up on the keyboard but it is grayed out. It is also grayed out on my menu bar. Coming out of the headphone jack is a red light. As soon as I plug my headphones back in, itunes open up and I get my audio. Any ideas whats going on?