Hi Kevin,
what do you mean by
In the meantime, I would like you to try replicating the problem to confirm this if possible.
As I allready wrote in my last post #127: I flashed the BIOS to 0324 and the problem persists.
New installation of video driver 10.18.10.3345 with included HDMI audio driver 6.16.00.3129 didn't fix the problem as well. I'm using Win 8.1 Pro 64-Bit.
So the problem is not solved. What should I replicate?