Behold, software version L622 showed up yesterday and all my 129 afflictions are healed! The red x at 129 has magically turned green and my 722 stops searching for the unattainable 129 conus channels every time I turn it on in the morning. The 129 conus channels still show up in the guide (red for nats and "available" for premiums), but apparently the receiver now doesn't care that it can't really find them.
That's great news!