I'm having issues with getting X working on an MD (see
http://forum.linuxmce.org/index.php?topic=10720.0) and am also heading towards the sort-X-out-first approach of Kevin below. His was on the core, whereas mine is on an MD and what I'm struggling with at the moment is getting the relevant xorg.conf file to be used... as you will see from my post, in my situation, stopping Xconfigure.sh from changing the file isn't enough... once I've done that, somewhere in the reboot the xorg.conf file seems to be deleted and then the X-server startup is falling back on some default settings.
May not be a problem for you but something to watch out for.
James