Getting Error, why?

[Kungfu]

Fatal error: Call to a member function query_first() on a non-object in /public_html/forum/includes/functions.php on line 1002

Last night i was integerating vbulletin with another script of mine, it was working perfectly too. Then i commented it out because i wasnt done with it yet and thought i would finish today. Well when i went to go include my script that gathers the persons info i got this.

i use another script to get all that junk which calls on
require_once('/public_html/forum/includes/init.php');

and when that happens it loads everything up in vbulletin so we can read the sessions and all that. Well it gets to that functions line which is
$user = $vbulletin->db->query_first("

and it bugs out, anyone know why this is.

Last night it was working fine and not giving that error.