Have a new Denon 2803 and finally paid a pro to hook it up due to a hum from my subwoofer. He found a ground fault in the cable in to the cable box. He ordered an isolator and it fixed the hum. Problem is that I also lost five starz and two HBO channels. I took the isolator off and all channels worked. The sub is unhooked now and am wondering if anyone knows what I should do. I will call the installer tomorrow and see if he has an answer. Thanks.