HI,
i'm currently using the same system as PityOnU: Asus M004U with Windows 8.1 64-bit except I'm using a USB soundcard with an optical output (Turtle Beach Micro II). This configuration works well with XBMC: I get dolby surround sound from my Denon receiver via the optical output of the USB soundcard. The problem happens when I run Netflix and select Dolby Digital+: The framerate drops to maybe 2 frames per second and there is no sound but everything run's smoothly if I select Stereo. Maybe this is caused by the same thing as what PityOnU is experimenting...
thank you.