Audio issue in recently added movies (5.1+) in 2.0 audio environment?!

[FBK]

Hey guys,

I'm running a fresh installation of 1.0 RC3 and have problems playing some recently added movies. I have the feeling that it has something to do with my audio output (2.0 HDMI) and the audio layers in these few movies (5.1 / 7.1 & A_DTS). However I have no knowledge of audio codecs and their ability of being played under xbian at all, so this is why I need your help!

Software
XBian version: 1.0RC3
XBMC version: 13.2
Overclock settings: default

Hardware
Power supply rating: /
RPi model (model A/B 256mb/512mb): B
SD card size and make/type: /
Network (wireless or LAN): LAN / static
Connected devices (TV, USB, network storage, etc.): TV, USB-HDD

Logile
Link to logfile(s):
xbmc.log
guisettings.xml
Video-Info-File

Problem description:
Whenever I play this movie (and some others) I don't receive any audio except for the a few milli seconds when I stop the movie. I am a total noob, if it comes to audio and video protocols/variants, so my main issue is finding out, which parameter(s) in these movie files cause my audio problems! Please help. You find my audio settings in the <audiooutput> arena of the guisettings-pastebin and the movie nfo.file in the Video-Info-File-pastebin obove. Probably wrong audio layer for my configuration?! Thanks for your help!

How to reproduce:
Just play movie. Recently added movies play without any audio.