Comcast Catch-22: recording vs. DVR handshake

I have a Comcast/Motorola DCX3400 DVR with two tuners and a Sharp Aquos TV. Sometimes I get into a bind. Consider these two facts:

1. If the DVR is turned on before the TV, then the DVR doesn't know about the TV. This seems to be a "feature". The result is that "graphics" (which includes "My DVR", "Menu" and "Guide" displays) are disabled.
At first I thought this was due to missing the HDCP handshake, but it fails the same with with HDMI and component video. (Yes, I disconnected HDMI while testing component.)

2. If the DVR is in the process of making a recording, the recording will be terminated if the DVR is shut off. As a former TiVO user, I'm outraged at this "feature", but that's an issue for another time.

Things go bad when I come home and want to watch a recorded program while the DVR is making a recording. I turn on the TV and fact #1 comes into play. I can't use the My DVR button to play the recording. I could fix that by turning the DVR on and off, but then fact #2 comes up. It would kill my recording if I did that. The only cure seems to be to turn off the TV and read a book until the recording is done.

By the way, the double-arrow icon on the DVR front panel has been flashing for a couple of months. I haven't seen anything which explains what that means. Could that be related?

You may not be surprised to learn that the Comcast representative at was clueless. I'm not a masochist, so I don't want to try to explain this over the phone to tech support.