If you lose OTA scanning on your Genie, all hope is not lost. I got mine back by following seemingly wrong advice.
I forget that if I learned how to do this on here or the "other" one, but here's what you do. It did work for me...
-Re-do the initial set up on your AM21.
-When you re-set it, put your real zip code in the primary. If you use a real secondary zip code, input that as well.
Are you missing a channel? Do this now:
-Reset the AM21 again (initial set up).
-Input your primary zip. HOWEVER, do NOT put in the secondary zip you normally would. Instead, input a zip code for ANY DMA that has the desired subchannel numbers and are in the Directv database of stupidity. RF frequencies do not seem to matter. Sometimes, you can find the same affiliate (Metv, Antenna TV, etc). The database can be downloaded on the "other" site. The missing channels from the 3rd zip are added to the list. The previous set up, however, remains. It seems to just keep building on it. I did it with 3 extra zips and it didn't erase anything, just added the missing channels.
Some of you are shaking your head right now, thinking I am an idiot. Don't worry, I don't blame you. I argued with the original poster about how this wouldn't work until they just told me to try it. And it DOES work. I have x740 software, HR34, and AM21.
Yes, it's annoying and time consuming. But it worked for me and a few others so at least try it when you get x740 software. I got 6 cities in my guide - Greensboro NC, Raleigh NC, and Roanoke VA are really what the listings state (true locals), but I have a few subchannels from Indiana, Memphis, and Vermont in my guide to make subchannels recordable. It's easy to create a TitanTV custom guide with just the missing channels to actually see what's on.
(Note: if you RBR or download a CE, you have to re-do the set up.)