Warning: array_shift() expects parameter 1 to be array, string given in boost_boost_menu_router()

Hi,

I'm getting this error when not logged in and trying to access an unauthorised page that contains a view. The code that is causing this is:

  // Handle views.
  if (isset($parts['menu_item']['page_callback']) && $parts['menu_item']['page_callback'] == 'views_page') {
    $parts['menu_item']['page_callback'] = 'view';
    $parts['menu_item']['page_type'] = array_shift($parts['menu_item']['page_arguments']);
    $parts['menu_item']['page_id'] = array_shift($parts['menu_item']['page_arguments']);
    // See http://drupal.org/node/651798 for the reason why this if is needed
    if (is_array($parts['menu_item']['page_id'])) {
      $parts['menu_item']['page_id'] = array_shift($parts['menu_item']['page_id']);
    }
    return $parts;
  }

I'm not too sure if this is a bug or a problem with my view because the string that is under $parts['menu_item']['page_arguments'] is:

string(60) "a:2:{i:0;s:25:"revisioning_content_admin";i:1;s:6:"page_1";}"

Any help would be appreciated!
Cheers,
Z