Emacs needs to be linked with the static version of the X11 library, libX11.a. This may be missing.
Under OpenWindows, you may need to use `add_services' to add the `OpenWindows Programmers' optional software category from the CD-ROM.
Under HP-UX 8.0, you may need to run `update' again to load the X11-PRG `fileset'. This may be missing even if you specified `all filesets' the first time. If libcurses.a is missing, you may need to load the `Berkeley Development Option' {???}.
If you are building the MIT X11 sources, you may need to modify your `site.cf' file to get static versions of the libraries. (Info from David Zuhn <zoo@cygnus.com>.)
Other systems may have similar problems. You can always define CANNOT_DUMP and link with the shared libraries instead.
To get the Xmenu stuff to work, you need to find a copy of MIT's liboldX.a.