Repost - Constraint - Referencing

Hi EveryBody,

I'm experiencing some problems referencing a key from another table when placing a constraint on a column in another table. I have recreated the problem with some simple tables and the session is logged below.  

I will appreciate any help that explains why I am getting the error, I followed the note's in the Oracle guide - but according to them, this should work * hah *  

Thanks In Advance
AA    

SQL> create table aa

     (alpha number(10),
     beta number(10),
     theta number(10))
     STORAGE (INITIAL        1M
     NEXT           500K
     MINEXTENTS     1
     MAXEXTENTS     10)

 Name                            Null?    Type
 ------------------------------- -------- ----
 ALPHA                                    NUMBER(10)
 BETA                                     NUMBER(10)
 THETA                                    NUMBER(10)
 

SQL> alter table aa add primary key(alpha,beta,theta);  

Table altered.  

SQL> create public synonym aa for aa;
 Synonym created.  

SQL> create table b

    ( gamma number(10) constraint gamma_fk references aa(alpha))

    STORAGE (INITIAL        1M
             NEXT           500K
             MINEXTENTS     1
             MAXEXTENTS     10)

                                                     *