I have DirectTV and 3 non-HD Tivo boxes. I want to upgrade my DirectTV to HD but understand that the TIVO HD boxes are not compatible with Direct TV. Therefore, I would like to get the DirectTV HD-DVR to record any HD programs that I want to see and use my Tivo boxes for the non-HD. Can I use both a TIVO box AND an HD-DVR on the same television? Has anyone set up a TV this way? I don't want to give up the TIVO, partly because I like the TIVO and partly because we have all our TV's networked. Thanks for any advice.