/admin/reports/system_status menu hook not respected

I'm noticing that some sites fail to report their modules and instead return a 301 or 302 page redirect.

This is most probably caused by another module, that hooks in before system_status_menu()

/**
 * Implements hook_menu().
 */
function system_status_menu() {
  $items = array();

  $items['admin/reports/system_status'] = array(
    'title' => 'System Status',
    'description' => 'Output of the System status module',
    'access callback' => 'system_status_access_callback',
    'access arguments' => array(3),
    'page callback' => 'system_status_status_page',
    'file' => 'system_status_status.page.inc',
    'type' => MENU_CALLBACK,
  );
  return $items;
}

The question is 1) what kind of module/hook/callback could cause this, 2) how can we prevent this from happening.