I have two 722k receivers the program guide is fine on the one the other has limited programming listed, I rebooted the unit and I still come up with some channels that list "No Information Available"
Rebooting will in general not reload the guide if the receiver thinks it has a recent copy on disk. The switch check is usually the method of choice for getting the receiver to reload (unless you have a 922).
What happens if you bring up the guide and arrow right until it runs out of info?
Normally if I arrow to the right at say 5 days out it will say that the program guide is out of date and the choice to update. Not this time but I will do a check switch test to see what happens