Question: maplev, emacs and the use of mint

Hello,

First of all I would like to thank Joe Riel and congratulate him for the great maplev mode for emacs.
If any of you use it I would appreciate a little help with running "mint" from emacs.

Here's what the maplev specific part of my .emacs looks like,

;;; automagically load .mpl files in maplev-mode ;;;                                                                                                                              
;;; by Joseph S. Riel ;;;                                                                   

                                                                                      
  (autoload 'maplev-mode "maplev" "Maple editing mode" t)
  (setq auto-mode-alist
      (cons `("\\.mpl\\'" . maplev-mode) auto-mode-alist))

(custom-set-variables
  ;; custom-set-variables was added by Custom -- don't edit or cut/paste it!                                                                                                      
  ;; Your init file should contain only one such instance.                                                                                                                        
 '(maplev-executable-alist (quote (("11" "~/work/maple11/bin/maple" nil "~/work/maple11/bin/mint") ("10" "maple" nil "mint") ("9" "maple" nil "mint") ("8" "maple" nil "mint") ("7\
" "maple" nil "mint") ("6" "maple" nil "mint") ("5.1" "maple" nil "mint") ("5" "maple" nil "mint") ("4" "maple" nil "mint")))))

(custom-set-faces
  ;; custom-set-faces was added by Custom -- don't edit or cut/paste it!                                                                                                          
  ;; Your init file should contain only one such instance.                                                                                                                        
 )
 

If I run mint from the menu (C-c <return> b) I get the following message,
Invalid argument 3
in the mini-buffer.
and if I try to type,
C-c ENT b,
I simply type a "b" in the buffer with the .mpl file.

Sorry if this is a very trivial mistake but any help is appreciated,

Thanks in advance for any help,

Cheers,

Alvaro