XBMC Newbie and CEC Stopped working

[IriDium]

I haven't tried it but it might solve the issue.
I assume your system is fully up to date.

sudo nano /etc/apt/sources.list -> Add new line deb http://xbian.brantje.com staging main.
sudo apt-get clean
sudo apt-get update
sudo xbian-config -> 5 -> 3 Select xbian-package-cec (Should be the only one)
sudo reboot

See if that improves matters.