Mini Box mandatory software update fails

When my mini box boots up a pop up shows mandatory software update is available.  I press select and it shows update, 0%, then 10 seconds later it shows software update can not be installed correctly. The box does not reboot, it just continues until a program is displayed. Every 10 minutes the pop up returns for the mandatory update and when it fails it goes back to the program I was watching. I thought it was a bad mini box and returned it for another box. The replacement does the exact same thing. Nobody can tell me if the filter on the pole is blocking the frequency of the update signal.

Has anyone else had this problem?

I also can not get channel 15 but the cable card in my TIVO gets it fine. Channell 15 is also fine WITHOUT the mini box.

(service area is North Kingstown, Rhode Island)