It looks as if you are right. Direct TV must be transmitting HD through the SD satellites on those channels. I hooked my laptop up to the KVH system and verified the antenna is locked on the same satellites it always has been. My Samsung TV has to reset itself when I switch to and from those channels which tells me it is changing resolution. I do have 16:9 aspect ratio set for all channels so the picture size really doesn't change but the quality does. But why those channels??