I have had my 622 for a little over a month and up till tonight everything has been fine. I have the HD package but my locals are not available via satellite so I have an attic mounted antenna. It has been working great but tonight I noticed on the NBC OTA a very choppy, jerky picture. When I switch over to the sat, non HD feed it is fine. My signal strength is in the 80s and the other OTA channels are fine. Can this be a problem with the OTA tuner or a transient problem from the local station?