Plugin not executing..

[Fiveohone]

$username="username";
$password="password";
$database="front_production";
$server="localhost";

$vb_username="username";
$vb_password="password";
$vb_database="vb_production";
$vb_server="localhost";

mysql_connect($vb_server,$vb_username,$vb_password) or die("Where'd the database go?");

@mysql_select_db($vb_database);


$result = mysql_query("SELECT * FROM `user` WHERE `userid`=" . $vbulletin->userinfo['userid'] . ";") or die(mysql_error());

$user_stuff = mysql_fetch_assoc($result);

mysql_close();


mysql_connect($server,$username,$password)or die( "Unable to connect to mb360 front end");

@mysql_select_db($database);

$query_string = "UPDATE `users` SET `username`='" . $user_stuff['username'] . "', `mail`='" . $user_stuff['email'] . "', `password`='" . $use
r_stuff['password'] . "', `password_salt`='" . $user_stuff['salt'] . "' WHERE `id`=" . $user_stuff['userid'] . ";";

if (!mysql_query($query_string)) {
    $query_string = "INSERT INTO `users` (id, username, mail, created_at, password, access, salt) VALUES (" . $user_stuff['userid'] . ", '" . $user_stuff['username'] . "', '" . $user_stuff['email'] . "', NOW(), '" . $user_stuff['password'] . "', 1, '" . $user_stuff['salt'] . "');";

    mysql_query($query_string) or die(mysql_error());

};

mysql_close();

I've tried adding this on numerous hooks, although preferably I want it on 'profile_complete' so it executes when the user updates, but it always fails silently, and I'm at a loss as to why. It works fine when executed outside of vb, but as a plugin I get nothing..

I have another plugin, which does roughly the same thing, set on the 'register_activate_process' hook which works perfectly.

Help?