Re: Customization problem

[Richard Stallman]

    In this case, a third-party library uses `custom-set-variable'. This is done
    via `kill-emacs-hook' using this function:

    (defun icicle-control-reminder-prompt ()
      "If `icicle-reminder-prompt-flag' > 0, then decrement it and save it.
    Used in `kill-emacs-hook'."
      (when (and (wholenump icicle-reminder-prompt-flag)
            (> icicle-reminder-prompt-flag 0))
        (condition-case nil
            (customize-save-variable
              'icicle-reminder-prompt-flag
              (1- icicle-reminder-prompt-flag))
          (error nil))))

It uses customize-save-variable.  It does not (that I can see)
use custom-set-variable.  custom-set-variable is only supposed
to be used in the user's custom file.