So my HD channels have traditionally been in the 700's. I have some in the 1100's as well. Just this week, I can no longer view HD channels in the 700's (on both TiVo's). I do see the 1100's and the SD channels. Comcast did not make me aware of any programming/channel lineup changes and they could not successfully ping my TiVo box from their office. When I tuned to one of these 700 channels, I get "Channel not available". Thoughts?