I have a Sony 40" LCD with built-in HD tuner. I also have Comcast standard cable. It appears that I am receiving HD channels even though I don't have a cable card installed or have a set top HD box. If I tune in to Fox for example, I can receive (2) versions of the channel. I get channel 2 and channel 2.1. The former is standard analog and the latter comes through in widescreen and I believe 720p. Is this really HD? It seems sharper, but maybe it is not true HD.