I have just upgraded my DTV to the same thing . I already had the correct DVR but needed to update the my 2 other receivers. The Direct TV people installed all of this for me and did the setup. It works flawlessly.
I of course followed them around to see what they were doing. You did not mention if you installed a wall wart powered white box labeled "Connected Home Adapter" DECA1MR0-01. This has a Mac address and your router connects this to your Sat Dish.
What they did on mine was to run a cable from the adapter though a new cable wall connector to the outside and to the Sat dish.
Also when they were doing the setup they could not get it to work through one of the new receivers no matter what they tried but went to a second new receiver and were able to do the setup there. And like I said everything has functioned as it should since the install. Hope some of this helps you.
