According to Wilt:
Having said that, you need to set the box to output 1080i only. There is a red button in front of the receiver. see this picture
Here
You need to press this button, as you press it you will see the red lights lit.
The resolution goes like this:
To get a standard 1080i output when the top long light (in front of the receiver) is lit,
720p for the next light below it,
480p below that and 480i for the light below that. The next push of the red button puts you in a 'native output' mode (where all lights briefly flash) which will output whatever the resolution of the broadcast is.
Get it to 1080i. That is only the top light is lit.