I have installed XBMC (team-xbmc PPA) on my laptop (Kubuntu 10.10) and the sound from 5.1 movies isn’t downmixed correctly to stereo, even though the option is enabled. I have already tried http://forum.xbmc.org/showpost.php?p=587582&postcount=286 and it didn’t change a thing. Other players (VLC…) can do this correctly.
Any suggestions?