I was unable to run XFree864.0 as non-root (it was complaining about not being able to write to the log in /var/log. To fix I had to chmod +s /usr/X11R6/bin/X -- don't know if this is actually required, safe, etc.
I think this should be marked as a duplicate of BUG 12014 (No Xwrapper) ?!
*** This bug has been marked as a duplicate of 12014 ***