[grenma]

I'm assuming you have the same codebase as us, but it is the trigger_error in this function:

/**
* Constructor - checks that the registry object has been passed correctly.
*
* @param vB_Registry Instance of the vBulletin data registry object - expected to have the database object as one of its $this->db member.
* @param integer One of the ERRTYPE_x constants
*/
function vB_DataManager(&$registry, $errtype = ERRTYPE_STANDARD)
{
if (!is_subclass_of($this, 'vB_DataManager'))
{
trigger_error("Direct Instantiation of vB_DataManager class prohibited.", E_USER_ERROR);
}

if (is_object($registry))
{
$this->registry =& $registry;

if (is_object($registry->db))
{
$this->dbobject =& $registry->db;
}
else
{
trigger_error('Database object is not an object', E_USER_ERROR);
}
}
else
{
trigger_error('Registry object is not an object', E_USER_ERROR);
}

$this->set_error_handler($errtype);

if (is_array($this->bitfields))
{
foreach ($this->bitfields AS $key => $val)
{
if (isset($this->registry->$val))
{
$this->bitfields["$key"] =& $this->registry->$val;
}
else
{
trigger_error("Please check the <em>\$bitfields</em> array in the <strong>" . get_class($this) . "</strong> class definition - <em>\$vbulletin->$val</em> is not a valid bitfield.<br />", E_USER_ERROR);
}
}
}
}