I have the Yamaha RX-V1700. I have it hooked to my TV via Digital Optical Cable. I have my receiver set to straight. So a Dolby Digital signal is coming thru while watching HDTV with antenna. FOX that is. Why is it that when the actual program comes on it sounds a lot quieter and when it is commercial time my speakers explode with power and the 5.1 surround really kicks in. It sounds good like that until the damn program we are watching comes on. Why is that and is there something i'm not setting right?