The guide/menus etc; run off a different data table for the information that they display however they will load without having sat signal at all. As will your menu etc;:
The guide information is nearly a static screen that is loaded into the receiver's memory. It contains only a fraction of the bits of information that even an SD picture requires, and the guide is not an active data stream except at download. Download happens when the receiver is turned off--unless you never turn it off and then you get to wait for it.
You might want to start reading some of the science behind digital systems.
From: "How Forward Error-Correcting Codes Work"
"Represented graphically, the general error-performance characteristics of most digital communication systems have a waterfall-shaped appearance. System performance improves as the signal-to-noise ratio increases."
I posted this issue in another thread before this one was even started. I saw this issue months ago and have to do a reboot when it starts doing that. This is one of the biggest bugs I have seen with the 722.