Error with complex Oracle query

$this->db->select("pu.username,
      pu.last_name,
      pu.first_name,
      pu.middle_name,
      ppi.passport_number,
      ps.passport_status_desc,
      pmax_status_date
    FROM  
      passport_users pu,
         (select pi.username,
                 pi.passport_number,
                 max(pid.passport_status_date) pmax_status_date
          from passport_information pi,
               passport_information_detail pid    
          where pi.username = pid.username
          group by pi.username,
                   pi.passport_number) p_max_status,
       passport_information ppi,
       passport_information_detail ppid,
       passport_status ps
    WHERE pu.username = p_max_status.username
       and pu.username = ppi.username
       and ppi.passport_number = p_max_status.passport_number
       and ppi.passport_number = ppid.passport_number
       and ppid.passport_status_date = p_max_status.pmax_status_date
       and ppid.passport_status = ps.passport_status
       and sysdate between ppi.passport_issue_date and NVL(ppi.passport_expiration_date, sysdate)", FALSE);

---------------------
I don't think it is embedded...

Then why when I run the query in Toad for Oracle, it works fine. It also works fine in CI, with the exception of when I try to do a footer search.

The following function is called when doing a footer search:

         foreach ($this->column_search as $item) {
             if ($_POST['search']['value']) {
                 if ($i === 0) {
                     $this->db->group_start();
                     $this->db->like('LOWER(' . $item . ')', strtolower($_POST['search']['value']));
                 } else {
                     $this->db->or_like('LOWER(' . $item . ')', strtolower($_POST['search']['value']));
                 }

                 if (count($this->column_search) - 1 == $i)
                     $this->db->group_end();
             }
             $i++;
         }

And by looking at the results from last_query() when I try the footer search, the piece in red is appended. Do you see the difference?

SELECT * FROM (SELECT inner_query.*, rownum rnum FROM (SELECT pu.last_name, pu.first_name, pu.middle_name, ppi.passport_number from passport_users pu, (select pi.username, pi.passport_number, max(pid.passport_status_date) pmax_status_date
                                           from passport_information pi, passport_information_detail pid where pi.username = pid.username group by pi.username, pi.passport_number) p_max_status, passport_information ppi, passport_information_detail ppid, passport_status ps
                             where pu.username = p_max_status.username
                                and pu.username = ppi.username
                                and ppi.passport_number = p_max_status.passport_number
                                and ppi.passport_number = ppid.passport_number
                                and ppid.passport_status_date = p_max_status.pmax_status_date
                                and ppid.passport_status = ps.passport_status
                                and sysdate between ppi.passport_issue_date and NVL(ppi.passport_expiration_date, sysdate)
 WHERE LOWER(LAST_NAME) LIKE '%o%' ESCAPE '!'
 ORDER BY "LAST_NAME" ASC
 ) inner_query WHERE rownum < 11)

Now if I change the red WHERE above to an AND, once again it works in Toad for Oracle.