TCM Recorder App

Hi, after listening to Drew's presentation on the TCM IM2 stereo microphone, I decided to get one for my new iPhone 4S that I had purchased in mid-February. I've just installed the PCM Recorder app, but even though Drew seemed to be able to use the recorder app and microphone just fine, I'm stuck with my phone because no matter what I do I lose all audio output once I plug the microphone in, don't even get VoiceOver feedback. If anyone else is using this app, how are you doing it without any audio feedback, or is there something I'm missing that can fix this. thanks!