VirTeX-common-initialization in xemacs-packages/lisp/auctex/tex.el has
the following code.
  (if (= emacs-major-version 20)
      (make-local-hook 'find-file-hooks))
I'm using XEmacs 21.4.17, so the (make-local-hook 'find-file-hooks)
call is not done.
This results in the following lambda being added to global
find-file-hooks (yuck).
    (add-hook 'find-file-hooks (lambda ()
			       ;; Test if we are looking at a new file.
			       (unless (file-exists-p (buffer-file-name))
				 (TeX-master-file nil nil t))
			       (TeX-update-style)) nil t)
I would guess that the code should be testing if make-local-hook exists.
  (if (fboundp 'make-local-hook)
      (make-local-hook 'find-file-hooks))
-jeff