I have found that as my local channels have been changing RF transmitters as they turn off their analog transmitters I have had to perform the following operations to get the channels to work properly:
HR20-700: In Antenna Setup select "Reset Antenna Settings". After doing this run the "Initial Setup" selection. After I did this my non-working channels started to work. It is still not 100% as I think they are not reading the data from my local networks properly.
H20-100: This was harder. I could not just scan for new channels as my box got really confused. I actually had to go through the "Reset" - "Reset Everything" to get my channels right. The pain here was that it wiped out your favorite lists. However, after doing this and going through an entire rescan everything is much better.
The problems that I still have:
16-1 WVAW (RF 16.1) now shows up! Still only in SD, but they have done HD test signals. (Yeah!)
19-1 WCAV (RF 19.1) now shows up in HD! (Yeah!)
19-2 19NOW (RF 40.3) DOES NOT SHOW UP IN THE GUIDE.
27-1 (SD) WAHU (RF 19.3) now shows up. However, the HD version on RF 40.1 should probably be used.
27-1 (HD) WAHU (RF 40.1) DOES NOT APPEAR TO BE USED.
27-2 MyNetTv (RF 40.2) now shows up, but always shows searching for signal.
for this info from the station.
I think the problem is D* can't handle the funky stuff they are doing (27-1 in both SD and HD).
I hope this helps y'all and maybe someday they will fix the channels here in C'Ville.