Problem with Oracle Text query

 I have the following sql query:
SELECT  
 chg.chg_id, chg.datetime,
 chgtxtun.text user_name,   chgtxtco.text user_comment, 
 chg.operation,  chg.bnumber,
 chg.status,  chgtxtrn.text,
 chg.param1,  chg.param2,
 chg.role_type,  chg.bsk
 FROM 
    (changelog chg
      left outer join text_values chgtxtun on chg.tid_user_name=chgtxtun.id    
      left outer join text_values chgtxtco on chg.tid_user_comment=chgtxtco.id   
      left outer join text_values chgtxtrn on chg.tid_resource=chgtxtrn.id)
-------
  LEFT OUTER JOIN
-------
    (customer cus
    left outer join text_values custxt on cus.tid_name=custxt.id )
  ON cus.bsk=chg.bsk