function _wizard_recursive_form_defaults(&$defaults, $form, $depth = array()) {
  if(is_array($form)) {
    // Recurse into each child element (ie. anything that's not '#something')
    foreach(element_children($form) as $key) {
      $new = $depth;
      $new[] = $key;
      $form[$key] = _wizard_recursive_form_defaults($defaults[$key],$form[$key], $new);
    }
    // Now see if we have any properties (ie. '#something'). If we do, then
    // set a default.
    if(element_properties($form)) {
      // Attempt to set a default value for this form element. Don't do this
      // if it's a file type element - it doesn't work, and we'll actually
      // risk putting an entire file into the form as a default the browser
      // will ignore.
      if($form['#type'] != 'file' && isset($defaults)) {
        // Check if the special wizard default value is set. This can be used
        // to override normal behaviour. If it's there, it's used in preference
        // to anything else.
        $default_value = NULL;
        if(isset($form['#wizard_default_value'])) {
          // Use this over anything else
          $default_value = $form['#wizard_default_value'];
          unset($form['#wizard_default_value']);
        } elseif(!is_array($defaults)) {
          // We can use the default we have from the user data
          $default_value = $defaults;
        }
        // We can work around a problem in Drupal 5.1 by frigging $_POST
        // for checkbox form elements. See http://drupal.org/node/144482
        if(WIZARD_WORKAROUND_DRUAPL51_FAPI_BUG && $form['#type'] == 'checkbox' && isset($default_value)) {
          $code='$_POST[\'wizard\'][\'' . implode("']['", $depth) . "'] = '" . $default_value . "';";
          eval($code);
        }
        $form['#default_value'] = $default_value;
      } // end of if is file
    }
  }
  return $form;
}