I'm running xbmc stand-alone from the xbmc svn ppa right now. It's rather unstable for me atm so I haven't done a lot of testing yet I'm waiting for the offical ppa to be back online. I do have audio though using plughw:1,9 for custom output and passthrough without setting up a /etc/asound.conf
Ensure the user that xbmc stand-alone is running under is part of the audio group. I think xbmc stand alone requires you to create the user xbmc and add them to the necessary groups. My default user is xbmc so I don't have to mess with this stuff.
Xbmc should set this up automagically if not. List all users.
or simply cat /etc/passwd
cat /etc/passwd | cut -d":" -f1
If xbmc doesn't exist add them.
If they do exist check the groups for xbmc
sudo adduser xbmc --gecos XBMC
To add the necessary groups
only using --group as described in the links below or -G will strip any current groups and replace them with those defined above -a -G will add groups alongside any preexisting ones.
sudo usermod -a -G audio,video,netdev,fuse,cdrom,plugdev xbmc