I notice this on the local HD channels only. It sucks! I notice this especially on fox and it annoys the living hell out of me since I am a huge fan of 24 and Prison Break. My Fox HD channel is actually really bad. It will break up anywhere between 10-20 times when watching these shows with the micro blocking. The other channels are crisp and clear though. Its only the local HD channels that to this, particularily Fox more than any other channel.