I got a new TV with an integrated OTA HD tuner (ATSC). When I added my channels via autosearch, I noticed something odd: I got a channel 99 with multiple subcarriers (99-1, 99-2, etc). These channels were flagged with names of popular cable channels: ESPN, ESPN2, Food, HGTV, etc. At first these didn't work, any attempt to view them resulted in a "weak signal" message from the tuner. However- today I was able to get signal lock, although it only provided audio. The audio was absolutely from the channels in question (I heard Marc Summers on Unwrapped whgen tuned to the Food channel). I'm wondering how this could happen. These channels aren't HD, as far as I'm aware, and I dont know why they would be broadcasted over the air even if they were. Any thoughts?