The .emacs file contains (require 'mwheel), but when trying to use the
mouse wheel in xemacs I get a beep and a message button4/5 not defined.
In GNU Emacs the wheel works.
Argh. If you take a look at the mwheel.el from XEmacs, they initialize in a
slightly different way.
I'll fix it for /etc/skel/.emacs/
Fixed in emacs-20.7-35:
;; Enable wheelmouse support by default
(if (not running-xemacs)
(require 'mwheel) ; Emacs
(mwheel-install) ; XEmacs