full_mosey,
You're describing two different processes.
1. When you set up your dish the onscreen information can help to point the dish at the satellites which is necessary to get any signals. As you travel the location of the fixed satellite positions changes with respect to your current location and the dish has to again be pointed to the satellites. This is completely independent of what channels your receiver is authorized to receive.
2. You bought the receiver in Q and it was initially setup and authorized to receive the local Phoenix channels which was correct. In Texas you moved out of the Phoenix spot beam, called and were authorized to receive a Texas a spot beam and local channels, maybe Dallas?
As long as you remain in a spot beam you only need to do 1 above which was your initial experience traveling east. And then you reached a point in Texas where 2 was necessary.
The channels that you receive (both local and national) are controlled by your account and location. For example I would have to pay extra to get HBO and then my receiver would be authorized to receive HBO.
I have a decent source for DTV spot beams but not Dish. Perhaps someone has a source. Knowing the spot beam helps me to know when I'll likely enter/leave spot beams. Spot beams are not exact but rather the signal gets weaker as you move away from the center of the beam.
Welcome to the world of traveling with satellite.
