I live in the Houston area and have comcast cable with two DVR cable boxes. i recently hooked up a sony LCD tv with a QAM tuner and did a scan for all channels. It picked up the golf channel only which was 68.15. Why am I not getting the other qam channels? It was the same result at my previous address which was about a mile away. I also tried it with another lcd tv that I have hooked up to one of the cable boxes and still no channels over qam. Does Comcast broadcast over QAM in houston?