I think I found a fix on the AVS forum
use HDMI_2 & rename it to PC

"I have a DVI to HDMI converter (a couple bucks @ Amazon) on one of the connectors on my PC's nVidia video card. I have a HDMI cable running from that to HDMI2/DVI input on the TV, and have named that input "PC" in the TV's menu. I have a stereo mini plugged into the PC's sound card on one end which connects to the red/white RCA connectors for the HDMI2 input on the TV."

This method was mentioned in an around about/confusing  way in the manual.

I'll try it next week & post the results.