Resolution resets to 480 - DirecTV

The DVR receiver resets to 480p whenever I turn on the TV or change the channel. I have to manually press the resolution button to move it to 1080. Also, the max resolution I see on my set is 1080i. I'm not so concerned whether it's 1080 (i) or (p) as the TV is a bit older, however, the 480p issue is something I need to address.

This question, "Resolution resets to 480," is about DirecTV channels, programming, equipment, and sports.