Don,
All I can say is "WOW"! I guess the only "truth" here is that DirecTV it terribly inconsistent. I have followed forum posts about DirecTV over the past four years and viewed complaint after complaint about DirecTV's lack of support for RVers. Your post is the first I have heard about their tech support actually knowing how to connect to RV equipment. While it is good to hear they could provide you support, something in me says "you got lucky".
I'm glad you had such a good experience.
Bob