Yep. You found a typo in my text file.
change this
Code:
$ping_url = $vbulletin->options[hometitle], $vbulletin->options[bburl] . '/showthread.php?' . "p=$newpost[postid]";
to this:
Code:
$ping_url = $vbulletin->options[bburl] . '/showthread.php?' . "p=$newpost[postid]";