SQL in FORMS4.5 Problem

Here is an odd Oracle SQL situation. Notice we eliminated the sub-select because 'user' can be found in ANY Oracle Object. The BEFORE situation works for some Users but not all. The AFTER works for all Users. Why ?? One theory: The 'IN' is causing something weird to happen.

BEFORE:

      SELECT   lower(user)
      INTO     user_hold
      FROM     dual
      WHERE    lower(user)  IN
      (SELECT lower(user_id) from pi_administrator);
      
      
      
      

AFTER:

      SELECT   user_id 
      INTO     user_hold
      FROM     pi_administrator
      WHERE    lower(user)  =  lower(user_id);



Ideas ?      

-- 
Peter Douglas Hay, Project Manager, Boeing, PI Systems,
VOICE:(425) 865-4948 FAX:(425) 865-3555  HOME:(425) 641-6050
INTERNET: peter.d.hay_at_usa.net  Building:33-05 Mail Stop:7J80