function hook_form_alter($filter_form, &$form) {
  if (isset($form['type']) && $form['type']['#value'] .'_node_settings' == $form_id) {
    $form['workflow']['upload_'. $form['type']['#value']] = array(
      '#type' => 'radios',
      '#title' => t('Attachments'),
      '#default_value' => variable_get('upload_'. $form['type']['#value'], 1),
      '#options' => array(t('Disabled'), t('Enabled')),
    );
  }
}