Problem with sound (Extreme distortion)

[MacGreve]

So I recently bought Action! and I'm very happy with the results, that is when I record my own microphone. But when I record gameplay with two or more people their microphones are extremely distorted but system sounds, game sounds and my own microphone are normal. Warning! The link I'm about to post is extremely loud, I recommend turning the volume down, also it's in danish you probably won't understand what they're saying.

Here's an example: http://www.youtube.com/watch?v=0AWZrz74 ... e=youtu.be

I hope anyone have had this problem and possibly a fix, because I can't edit and upload gameplay if people are this distorted