I figured out that the message above is resulting from the HDMI connection between the DVD player and the monitor.
Not sure what to do about that. We go back and forth from my surround system to the built-in sound on the TV (depending on how late it is and who's trying to sleep!

- I just turn the volume all the way down on the TV when listening through the receiver). So now, if I want to listen through the TV speakers, I have to switch the DVD player from Bitstream back to PCM. Not a HUGE deal but a little clunky. Worse than that, if I stay with the surround system, that message keeps popping up.
Any easy ways to get around this?