Man this 8300HDC box is complicated and frustrating. I hope I'm not duplicating anything here. I downloaded the large manual but am mystified whether I should choose "fixed", "up-convert 1", "up-convert 2", or "auto". I went into the box and "turned on" 720p because I understand that is better than 1080i (my set is 720p/1080i). Do I also need to select either 480i or 480p in the initial setup? The instructions are worthless as are Comcast's people. I am connecting with HDMI. Any tips? Much thanks if so.

"Any tips? Much thanks if so."

Look at the 8300HDC threads in the Recorders section.