Different registration forms using different content types for profiles?

OK, I can't even get both content types to show on a single registration form at once. Am I doing something wrong?

EDIT: Never mind. Got it working. Here's the relevant code. It basically just reverses everything done in content_profile_registration_form_alter() ... there's probably a better way to do this:

  if ($form_id == 'user_register' && module_exists('content') && arg(0) != 'admin') {
    require_once drupal_get_path('module', 'node') .'/node.pages.inc';
    $all_profile_types = content_profile_get_types('names', 'registration_use');
    $used_profile_types = $all_profile_types;
    $unused_profile_types = array();
    $form += array('#field_info' => array());
		//check our URL for which profiles should be enabled.
		if($_GET['mode'] == 'child' && isset($all_profile_types['adult_profile'])) {
			$unused_profile_types['adult_profile'] = $all_profile_types['adult_profile'];
		}
		else if($_GET['mode'] != 'child' && isset($all_profile_types['child_profile'])) {
			$unused_profile_types['child_profile'] = $all_profile_types['child_profile'];
		}

    foreach ($unused_profile_types as $type => $typename) {
      // Initialize new node:
      $node = array('uid' => 0, 'name' => '', 'type' => $type);
      // Get the node form
      $node_form = drupal_retrieve_form($type .'_node_form', $form_state, $node);
      drupal_prepare_form($type .'_node_form', $node_form, $form_state);

      foreach ($node_form['#field_info'] as $field_name => $info) {
      	unset($form['#field_info'][$field_name]);
        unset($form[$field_name]);
      }

      $keys = array_keys($node_form);
      foreach ($keys as $key) {
        if (stristr($key, 'group_')) {
          unset($form[$key]);
        }
      }
    }
    
    if (!count($used_profile_types)) {
			if (($key = array_search('content_profile_registration_user_register_submit', $form['#submit'])) !== False) {
					unset($form['#submit'][$key]);
			}
			if (($key = array_search('content_profile_registration_user_register_validate', $form['#validate'])) !== False) {
					unset($form['#validate'][$key]);
			}
    }
  }