Thanks for all your suggestions. It turns out the answer is that if you have a link from /usr/X11 to /usr/X11R6 you must either change your /etc/manpath.config to have a line like MANDB_MAP /usr/local/X11/man /var/catman/local/X11 or given the default manpath.config file you must have a link in /var/catman from X11 to X11R6. -- Rob