I'm experiencing this issue as well. My setup is as follows
CPU: Intel Core i3 4340
MB: Gigabyte H87N-Wifi
OS: Windows 8.1 Pro N 64bit
Receiver: Onkyo TX-SR578
I have my HTPC connected straight to the receiver with an HDMI cable. Only thing going to my television (Sony KDL40W4000) is the output HDMI cable from my receiver. Now the surefire way I've gotten this bug to appear is by opening a tab of Google Play Music on Chrome (https://play.google.com/music/listen?u=0#/now), listening to a song and then pressing the power button on my TV's remote. When I turn the TV and the receiver back on by pushing the power button on my TV's remote again, the image comes back on once the receiver is on but no sound can be heard until a reboot (when sound is working my receiver shows a PCM light on the front, when the sound is turned off by this bug, the PCM light isn't on). If I only turn off my receiver (by using the receivers own remote), this bug doesn't appear and sound & image comes back once the receiver is back on.
My receiver is configured to utilize HDMI CEC so I can adjust the volume of my system with the TV's remote. I can also shut down the TV and the receiver by using the TV's power button on the remote. Maybe this issue is somehow related to HDMI CEC? I've attached my dxdiag files for when I have sound and when the HDMI sound isn't detected by Windows