Customization maxima mode

["Lorenzo Isella" <lorenzo.isella@gmail.com>]

Dear All,
I use emacs, among other things, also to edit some simple batch files
for the computer-algebra system maxima
(http://maxima.sourceforge.net/). Thanks to this mailing list, I
managed to add some simple customization to other modules (python,
aucted, R etc...), but for some reason this fails for maxima-mode.
An example from my .emacs file:

  (defun insert-round () "custom redefined insert-round" (interactive)
     (insert "()")       ; typing "(" automatically insert "()"
     (backward-char 1)) ;and go between them: no more matching problems!

(local-set-key "(" 'insert-round)

(add-hook 'Maxima-mode-hook
         (lambda () (local-set-key "(" 'insert-round)))


(setq auto-mode-alist (cons '("\\.max" . maxima-mode) auto-mode-alist))
;(setq load-path (cons "/usr/share/maxima/5.9.0/emacs" load-path ))
(autoload 'maxima "maxima" "Running Maxima interactively" t)
(autoload 'maxima-mode "maxima" "Maxima editing mode" t)

So, how comes that when editing e.g. file calculations.max, typing (
does not autocomplete to () and cursor in between the brackets?
I suppose I must be making a trivial mistake; a similar procedure
gives no trouble with a .py file for instance.
I should add that the maxima mode seems to be recognized (I have
syntax highlighting and so on).
Many thanks for your help

Lorenzo