Using FiOS in Eastern PA but lately have an unusual problem. The local CBS channel works fine on SD (Ch 3) but when viewed in HD (Ch. 503) it is subject to random and temporary occurrances of picture freeze, pixilation and loss of sound. This occurs on different HD set top boxes, on different TV receivers and it never happens when viewed in SD - whether being viewed via one of our HD set top boxes or an SD set top box. It never happens to any other HD channels.Is this a FiOS network issue or is it a possible ONT issue?