`A P' induces postscript error

[Karl Kleinpaste <karl@charcoal.com>]

I'm trying print a couple of mail messages today -- something I do
only rarely -- and everything I'm trying to print is rewarding me with
postscript errors, which begin as
           Error: /undefined in "
           Operand stack:
           HeaderLinesLeft   --nostringval-- --...
Is this something over which Gnus has control, or is this purely the
fault of the underlying ps-print-buffer-with-faces?

XEmacs 21.2.b31, with sumo tarballs from a couple months back.  I
probably haven't upgraded the underlying packages in 3+ months, and
haven't printed from inside Gnus for somewhat longer than that, which
is why I'm wondering which package, Gnus or ps-print, would be
responsible.

--karl