defcustom help requested

[Peter S Galbraith]

Hi all,

I'm tweaking a defcustom for MH-E and need a bit of help from someone
more knowledgeable than me.

The defcustom works well, producing a list structure the way I want it,
but I see the error message "invalid ((From ))" after clicking the first
two [INS] buttons:

As soon as I click on the "Value Menu" and select something, the message
goes away and doesn't hamper customization.

Am I doing something wrong that leads to this message?
Thanks.

Here's the code:

(defcustom mh-identity-list nil
  "*List holding mh-e personalities.
Omit the colon and trailing space from the field names.
The keyword name \"none\" is reversed for internal use.
Use the keyname name \"signature\" to specify either a signature file or a
function to call to insert a signature at point.

Example entries using the customize interface:  
   Keyword name: work
            From
            Value: John Doe <john@work.com>
            Organisation
            Value: Acme Inc.
   Keyword name: home
            From
            Value: John Doe <johndoe@home.net>

This would produce the equivalent of:
 (setq mh-identity-list
      '((\"work\"
         ((\"From\" . \"John Doe <john@work.com>\")
          (\"Organization\" . \"Acme Inc.\")))
        (\"home\"
         ((\"From\" . \"John Doe <johndoe@home.net>\")))))"
  :type '(repeat (list :tag ""
                       (string :tag "Keyword name")
                       (repeat :tag "At least one pair from below"
                               (choice (cons :tag "From field"
                                             (const "From")
                                             (string :tag "Value"))
                                       (cons :tag "Organization field"
                                             (const "Organization")
                                             (string :tag "Value"))
                                       (cons :tag "Signature"
                                             (const "signature")
                                             (choice (file) (function)))
                                       (cons :tag "Other field & value pair"
                                             (string :tag "Field")
                                             (string :tag "Value")))))))

-- 
Peter S. Galbraith, mh-e developer  <p.galbraith@globetrotter.net>
GPG key 1024/D2A913A1 - 97CE 866F F579 96EE  6E68 8170 35FF 799E
6623'rd GNU/Linux user at the Counter - http://counter.li.org/