Unable to autologin with other session than ubuntu

[glance]

I have a setup where lightdm auto logs in a xbmc user that runs a XBMC-session. I'm unable to have lightdm choose any other session than the default ubuntu one.

[SeatDefaults]
autologin-user=xbmc
autologin-session=XBMC
user-session=XBMC

None of the session settings bite, and it stills tries to start a ubuntu session:
[+0.06s] DEBUG: Seat: Failed to find session configuration ubuntu
[+0.06s] DEBUG: Seat: Can't find session 'ubuntu'

The xbmc user doesn't have a .dmrc and there is no one in lightdm's dmrc-cache.

I'm using lightdm 1.10.1-0ubuntu1 on ubuntu 14.04