I have 2 Trans Talk 9040 mobile phones and I have an unusual problem. Every once in a while, I can hear the person I am talking to fine, but they cannot hear me. I have had it happen most often when first making a call but I have also had it happen in the middle of a conversation. I have tried to see what common denominators there might be that might cause this, but so far I have nothing to help predict why this problem occurs. It can happen with either handset and I had the wall mounted radio unit replaced, but it still happens. Anyone got any idea? The service people from the company that sold it to me have looked at it several times but we can't seem to make it happen when they are looking at it. Any help will be much appreciated.