Ok think I found that problem as well.
Open hosting.php
Search For:
Code:
$db->query_write("DELETE FROM temp_host_request WHERE userid = '".$db->escape_string($vbulletin->GPC['postuserid'])."' ");
Change to:
Code:
$db->query_write("DELETE FROM " . TABLE_PREFIX . "temp_host_request WHERE userid = '".$db->escape_string($vbulletin->GPC['postuserid'])."' ");
Let me know.