path problem in auctex

Uwe Brauer writes:

 > (defcustom TeX-style-path
 >   (let ((path))
 >     ;; Put directories in an order where the more local files can
 >     ;; override the more global ones.
 >     (mapcar (lambda (file) (when file (add-to-list 'path file t)))
 > 	    (append (list TeX-auto-global TeX-style-global)
 > 		    TeX-auto-private TeX-style-private
 > 		    (list TeX-auto-local TeX-style-local)))
 >     path)

 > The issue is that TeX-style-path should contain also the value of
 > TeX-auto-private, /home/oub/tex/sty/auto
 > in GNU emacs it does, in Xemacs it does not. 
 > 
 > Is there anything in the above definition Xemacs does not
 > understand?

No.  Did you set TeX-auto-private to something other than `nil'?  If
you did, is it possible that there's a function that checks that the
file/directory exists and resets it to `nil' if it doesn't exist?
Perhaps there's a typo in your init file or other custom setting?