elisp issues on (cond ((when ...) t) ((when) t))

[Sebastian Meisel]

Hallo,

I'm trying to enhance my flyspell a little bit for german usage and succeeded 
in some aspects, but now come again to the shortcomings of my knowledge of 
elisp. I tried the following code:
------->
(add-hook 'flyspell-incorrect-hook 'flyspell-zusammen())

(defun flyspell-zusammen (beg end poss)
"Better spell-checking for german combined words."
(cond (
       (when (re-search-backward "\"-" (- beg 2) t) 
         (when (consp poss)
           (setq temp-buffer (get-buffer-create " *flyspell-temp*"))
           (save-excursion
             (copy-to-buffer temp-buffer beg end)
             (set-buffer temp-buffer)
             (goto-char (point-min))
             (setq word (capitalize (buffer-string)))
             (message word)
             (when (member word (nth 2 poss)) t) 
             ))) t)  ;;(when (re-search
      ((when (and (re-search-forward "-" (+ end 2) t) (re-search-backward 
"s" (1- end) t))
         (when (consp poss)
           (setq temp-buffer (get-buffer-create " *flyspell-temp*"))
           (save-excursion
             (copy-to-buffer temp-buffer beg (1- end))
             (set-buffer temp-buffer)
             (goto-char (point-min))
             (setq word (capitalize (buffer-string)))
             (message word)
             (when (member word (nth 2 poss)) t)
             ))) t) ;; (when (and (re-search
      ))
<------------

When I try the function without (cond) and with only one  (when 
(re-search ...) it works, but (cond ((when ...) t) ((when ...) t)) seems not 
to return nil as aspected, when both conditions fail. So no word are 
considered incorrect. 

What is the error I made?

-- 
Sebastian Meisel

(P.S. I apologize, that I incidently used german language in on mail before -- 
switching mailing lists need some concentration.)