I have an Icecast, and I've installed Airtime since 2 days ago. I have a problem with Master source and Show source, always airtime says me that: "There is no source connected to this input" but I have my microphone connected.
You have this in the wrong thread, it should be in airtime support.
Master and source are connected using a program like mixx or butt using whatever you have set up in the input stream settings page in airtime, under the system menu -> streams page. master will override all shows. source will only override the DJ you have scheduled.