I have same problem as JL Woodward on 5/25/2012. 722k w/mt2 OTA module. Suddenly lost OTA channels. Plugged antenna into TV & received all OTA channels. I reset, unplugged & reset, rescanned, then contacted Dish. They rebooted, rescanned & OTA channels briefly returned then went out again. I note that when I scan & select OTA channels & then return to Local Channels again none will be selected.