i have a DHS-E with 3 3x8 cards on it and a 2 port analog dispatch, we are having a wierd issue that comes and goes and can never reproduce it while onsite. so here is the problem: A caller will be on the phone on a co trunk or a intercom and you are able to here crosstalk from other phones or dtmf when one of them is dialing out. not just faintly it is loud and clear. any suggestion besides replace the cards?