ORA-3113 on FULL OUTER JOIN

 Hi all!
First of all, I don't know if this is the right community (topic) for this problem.

We have three cases with Oracle9iR2 9.2.0.6 and in two off them creation of a view with outer join fails (I know that 9.2.0.6 isn't really up-to-date):

CREATE or replace VIEW NKFAV83
( KU,
  HJ,
  FPL_JAHR,
  BETRAG) AS
SELECT KU, HJ, FPL_JAHR,
       SUM(CASE
                WHEN (BETRAG IS NULL)  THEN 0
                ELSE BETRAG
             END)
  FROM NKFAV02
WHERE MITTART = 'VE'
GROUP BY  KU , HJ , FPL_JAHR
;

 

CREATE or replace VIEW NKFKO97
(KU, HJ, PLANJAHR, VE)
AS
SELECT   NKFKO82.KU, NKFKO82.HJ, NKFKO82.PLANJAHR,
         SUM(CASE