link alter code

Trying to use standard link_alter code with nodereference_url supplied links, but not working.
Example test code:

function ela_link_alter(&$links, $node, $comment = NULL) {
  foreach ($links as $module => $link) {
    if (strstr($module, 'nodereference_url')) {
    unset($links[$module]);;
    }
  }
}

This will work with "generic" modules but not with NR_url. I presume I must use an if-statement incorporating widget or other expanded keys, but have not been successful in doing this.
Any help is appreciated.