Windows Media Center can't work if sound card is set as multiple channels?
Today I was trying to play a BD movie which has LPCM 7.1 sound. But my receiver only got "stereo" sound, no matter which software I used. I checked the setting, and changed the sound card's setting from 2 channels to 7.1. Then the sound card on Nvidia 450 may output LPCM 7.1 to receiver. The receiver displayed as "M. In 7.1". Usually if it's DTS-HD or DDHD, it will display DTS-HD or DD-HD MA. So that means the HTPC output multiple channel LPCM audio through HDMI successfully.
However, after the movie, I opened Media Center to watch OTA HDTV program. The Media Center only played for a couple of seconds, and looped for 3 or 4 times then crashed. Only after I change the sound card setting back to 2 channels, then go back to Media Center to set the audio as 5.1 or 7.1, it works fine. But that means if I play movies with LPCM in other softwares, I still get stereo, not multiple channels.
I've Googled and found other guys have the same problem.
I just don't get it that why Media Center can't work if the HDMI sound card set as 5.1 or 7.1. And it only can work if HDMI sound card is set as 2 channels?
Marantz NR-1608, LG 55UB9500 4K LED 3D TV, JBL HLS820, Klipsch Quintet III, Monster Cable THX subwoofer.