Easiest thing to do is boot into runlevel 3, mount your install disk, cd into the x directory on the disk and do
Code:
upgradepkg --reinstall --install-new
you could also download the x series from one of the current mirrors and do the same thing from the directory after you mirror the files. Lastly Robby has a thread here right now about call for testing where he is working out the bugs for the newest xorg packages which are available
here and the upgrade procedure is the same. So that's the easiest way I can think to go back, go current, or go into the future.
HTH
That's no guarantee to fix whatever your problem is. Just to upgrade X