Audio Issue. Please Help!

Dear All,

I am having a peculiar issue with my WD TV LIVE HUB’s audio when I play movie files. In the audio settings I have kept ‘Optical digital pass through’ and DTS and Dolby files play smoothly. But some files having dual audio do not have sound and I have to change it to Stereo. Some MKV files also have to be changed to Stereo for sound.

What could be the possible reason for this problem? Any help would be appreciated.

Anyone here faced a similar problem?