I have had this problem with a couple of people trying to connect with my server. It works for about 80% of people, but for those other 20, they will get in and connect fine, but no one can hear them, and Mumble doesn't act like they are trying to transmit. IE, if I were to hit a push to talk, it doesn't indicate that they are talking. They can be heard on the local loop back and with the audio wizard. I was wondering if anyone found a steady solution to this problem.