I recently got an SMT C5320 cable box from cablevision. I have it hooked up to an old analogue Sony Vega through S video. This box constantly put out green flashes all the time. It is the 3rd box that is doing it. Cablevision hasn't a clue why this is happening. The tv is 100% ok. It is something in the box. Called Samsung...they don't know either. Any Ideas. Cablevision's Scientific Atanta does not do this on the same tv.