Comment # 31 on bug 1112464 from Philippe Cond�

Hello,

Problem with nouveau is solved.

I installed the Nvidia proprietary driver. I needed to update the Xorg.conf
because Nvidia set the second monitor as disabled (nvidia-settings) after
multiple restart the second monitor worked.
But Nvidia doesn't work with the Xen kernel and I have some VM that I need.

So I uninstalled the Nvidia proprietary driver and re-enabled nouveau.
After Reboot the second monitor worked. I needed only to restore the desktop
configuration which has changed. 
Cannot explain what solved the problem

Thanks for your help
Philippe