Mac The Knife
Just a distant 3rd party observation, you need to find someone local that has a HD OTA system to compare notes to. The people at the stations that you're talking to may never admit what's going on or maybe don't even know what's going on. Some reception may be just boardline such that weather may impact it. My PBS reception is remarkably good at times, then for no obvious reasons, goes crazy, fluctuates and just disappears. The station would not admit to this, but someone I met through AVS forum that lives a few miles from here, confirmed this behavior.
As to your HS20 giving the HTPC message, I'm assuming that you've used it before and didn't get this message. Some DVDs, (Disney comes to mind) has an extra layer of copy protection that might give you this message when other DVDs don't. If you've got the Avia DVD, try it. If I recall correctly, they don't use any copy protection on it as to take away from picture quality. If you still get the HDCP message, then I'd say you've got a problem that needs fixing.
Let us know what's happening.
Samsung 64F8500, Panasonic 65VT50, Oppo 95, Tivo Roamio for OTA, Dish VIP722, Marantz AV8801 preamp, Rotel Amps, Atlantic Tech 8200 speakers, Seaton Submersive HP, Calman 5, Chromapure, Accupel DVG-5000, VideoForge HDMI II, i1Display3pro, i1pro2, eecolor colorbox.