I believe the answer to this is your location (Puerto Rico) assuming your dish is perfectly aligned.
The spot beams you have with higher levels means that indeed they're covering well the island......
But the conUS beam isn't 100% beamed to your area, their main target is with continental 48 states, and then shared with your area (USVI & PR), they aim in such a way that the spill over feeds your area with good enough power to have a respectable level of 80.
What size antenna do you have?
Here's a link so you can see the conUS beam shape:
Three Channel Master 1.1 M dishes which last over a decade
Edited by RG6-Q, 18 August 2013 - 11:40 AM.