Thanks for the welcome.
Yes, the summary is correct, HTPC to splitter and outputs of that to AVR (assume AV receiver) and TV directly, bypassing AVR.
Amp: Sony STR-DG920, TV: Sony 32XBR9
On the audio, I guess the TV only reports what it can physically handle. And bypassing the optical audio into the AV amp does serve the purpose, just defeats the purpose of "one connector for everything"
Your HDCP theory might apply. The NVidia graphics utility does report a secure HDCP connection in all combinations (AVR, TV, splitter). Now when I have the normal connection of PC->AVR->TV, the PC reports is is connected to the "SONY AV AMP", when I put the splitter in between, it says the connection is "SONY TV". On the AVR, I have the TV connected to the HDMI "OUT" connector and that plugs directly into the HDMI1 input on the TV. All the Bravia Sync functions work fine, TV remote controls AVR volume, etc.
I did give your "two connections to the TV test" a try and found that with the splitter connected to HDMI2 and HDMI3 on the TV, both inputs worked fine. So, taking it one step farther, I pulled out the HDMI2 cable and plugged it back into the AVR VIDEO1 input and darned if it all works now. I tried powering down the PC and the AV system (HDMI splitter power remained on) and turned all back on and it seems to be working as desired now. Maybe it was the HDMI splitter that was getting confused and put into a weird state and plugging it into only the TV cleared it up.
So thanks for that tip, I guess I'll have to remember that gyration to go through next time the power goes out and I need to bring things up again