[STUMP] undefine-key not working for me

Hi

I have rebinded some keys in my stumpwmrc. For example I have rebinded
"w" to show "windowslist" instead of "windows". But I also want to
remove the old keybinding. This is what I have in my stumpwmrc:

(undefine-key *root-map* (kbd "w"))
(undefine-key *root-map* (kbd "\""))
(define-key *root-map* (kbd "w") "windowlist")

"C-t w" now gives me "windowlist", but the old keybinding for windowlist
on "C-t "" still works, and both " and w is listed on the command overview
on "C-t ?". 

As I understand the manual that should be the correct syntax to
undefine a key, but I seem to have missed something, since it does not
work for me. What have I missed?

-- 
Niels