Error when usinf NCD Xterminal

[Kevin Handy <kth srv net>]

I am getting the following error twice (always 2 copies of this error)
on an NCD hmx Xterminal whenever I try to run anything using gtk.

Xlib: extension "XInputExtension" missing on display "sales:0.0"

Looking at xdpyinfo for the terminal in question, it lists
"XInputExtension" as being there, among many other extensions.
These programs work on older NCD Xterminals, and on some really old
NDS Xterminals, but not this particular model.

KDE programs will sometimes complain about a missing "RENDER"
extension, but they still run OK on this same terminal.
All the standard X11 programs (xterm, xload, etc) work without
any error messages.

What is causing this error, and is there any way around it?

If I can't figure this out, I'm going to have to switch over to the
KDE camp in order to get my work done. Tried motif/lesstif, but
that is even flakier than gnome. I need a widget set that works!