gnome on an NCD Xterminal

[Kevin Handy <kth srv net>]

I'm trying to write/use gnome software for a NCD/HMX Xterminal and
get an error something like the following (I copied the messages onto
a floppy from the customers system, but it is unreadable on this
system, so I am generating it from memory)

xlib: missing extension "XInputExtension"

however, if I look at 'xdpyinfo' for this terminal, it lists
'XInputExtension' as an existing extension. I've tried several
window managers (mwm, fwvm2, WindowMaker), but it didn't change
anything.

It works on other models of NCD Xterminals as well as some NDS
terminals.
KDE programs will sometimes complain about a missing "RENDER" extension,
but they still run (and xdpyinfo doesn't list a RENDER extension).
All gnome programs seem to give this error. All the standard 'X'
programs seem to work fine (xterm, xload, xdpyinfo, etc).

This is on a basic RedHat 7.1 install (with whatever versions of
everything that came with 7.1). 

What is causing this error? Why is only gnome/gtk affected?