Comment 2 for bug 212191

Hello,

Newer versions of Xorg support dynamic monitor support via the XRandR extension instead of XINERAMA, so while this is an unexpected change, it is not a bug. You may have to update your /etc/X11/xorg.conf configuration file; a good approach may be to back up your old xorg.conf and have the X server generate a new one to start with.

For more information see:
    http://www.x.org/wiki/Projects/XRandR
and in particular, the link for configuring an Intel server for Dual Head use.