user id not passed in url in admin cp

[derfy]

Simply put, we hijack register.php and run our own registering routine, inserting the new user data afterwards.

All of the users that have registered using our method don't have a valid id passed in the edit part of user.php in the admincp. The links look like:

http://community.purevanity.net/admincp/user.php?do=edit&u=

However, all previously existing users have their id passed.

It looks like the problem code is:

PHP Code:

if ($vbulletin->GPC['display']['username'])
{
$cell[] = "<a href=\"user.php?" . $vbulletin->session->vars['sessionurl'] . "do=edit&u=$user[userid]\"><b>$user[username]</b></a>&nbsp;";
} 


For some reason, $user[userid] is null when handling one of our registered users, but not others.

Any ideas?