I think Dish has been offering free HD for many years. I doubt that's the issue. The Tailgater does not have a check switch option so it's hard to tell what's going on. You do need to be able to point to the 129 satellite for nearly all HD programming. If you are currently in San Diego that should not be an issue but if you are on the East Coast (or in the trees) it could be.
If "I" was going to replace my portable Dish antenna I would buy the Pathway X2. It works in a similar manner as the Tailgater but has a much larger antenna and alllows for the use of Eastern Arc as well as the Western Arc satellites.