D34010WYK + USB SoundCard + Netflix Win 8 App + 5.1 Sound = No go

Hi,

I recently bought an External USB Sound Card to get optical SPDIF out from my NUC. It works perfekt in Windows Media Center and outputs Dolby Digital, DTS and Dolby Digital Plus to my Receiver.

Amazon.com : Sewell SoundBox, External USB Sound Card, 7.1 and 5.1 Channel Audio : Computer Audio Interfaces : Computers & Accessories

But in Netflix Win 8.1 App when I choose 5.1 Dolby Digital Sound, the Video fps goes down to like 1-2 frames per second and I have no audio output.

I have read that the sound card should be working with Netflix.

I have also read in these threads that Intel HD graphics may have sound problems with Netflix:

Re: Windows* 7/8/8.1 Driver (32 & 64 bit) Version 3345

Netflix, D34010WYK and 5.1 audio

Is this an known Issue with Intel NUC? In the last thread I read that the problem was solved by disabling legacy boot in bios, but I can't do that without reinstalling windows 8.1 to use UEFI boot.

All drivers, bios and windows update is the latest.

Any help on this is appreciated!