Would it be possible to get a DVR from a source other than direct tv (say craigslist or ebay) and hook it up to a Direct TV HD receiver and have it work?

EPG stuff is not really important.

Good try!

But the answer is no!!!!

To get the receiver to work you will have to have Direct activate a smart card. One hopes that the card will come along with the receiver. If not, you can get one from Direct.

Additionally, Direct also has to activate the recording mode of the receiver.

No matter what, you will need the smart card activated. Activated = paying Direct for the receiver and its recording mode to work for you.

Sorry!