We have been discussing the issue in another thread & a few of us have been having the same problem. Try the following to fix it
1. Perform a factory reset by holding down the VCR / DVR button & the on/standby button on the receiver simultaneously (you will lose all your custom settings)
2. Go into the setup menu & select Hardware Setup, then HDMI
3. Turn on HDMI Control (RIHD)
4. Hit the return button to edit out of the menu.
This should enable HDMI Through, but some people have had the issue pop back up again. In that case, you might need to perform steps 1-4 again.... Might need to also add some sort of voodoo ritual with a dead chicken for good measure.
In all seriousness, there seems to be a firmware bug. Maybe it will get addressed in a future update, but that's the way it goes with new electronics anymore. Good luck!