Well, you'd think that, but here's the twist. This morning, I fired up the LN46C750 with my satellite receiver connected to HDMI 1, and received the "no signal" message. Then I took down my 22" B series Samsung from the kitchen and fed the satellite receiver to its HDMI input and all worked as expected. I tried the 2310CI's output on the 22" as well and all worked as expected. When I reconnected the AVR to the LN46C750 HDMI input 1, it came right up as though nothing had ever happened.
It's starting to seem like some insidious handshake/hdcp thing, but I can't figure out what sets it off or if it is just an issue with the Samsung.