I had a similar issue with a low-power station here in Phoenix airea with 7.1,7.2,7.3 ... I live in zipcode 85248, a Chandler, Arizona zipcode. I tried the solutions suggested above, but the channels were not available to be reassigned to a similar channel like the solution stated. The only way I could get them to work was to switch my zip code to 85044, which is a phoenix zip code. Now the guide data is available for the channels.