Problem using dbms_metadata.get_ddl with remote database link.

 Dears!

I have a litle problem as I show below:

My oracle version is:

Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bi

PL/SQL Release 10.2.0.3.0 - Production

CORE    10.2.0.3.0      Production

TNS for Solaris: Version 10.2.0.3.0 - Production

NLSRTL Version 10.2.0.3.0 - Production

On Server 1:

There is a user named "DBLINK_USER" that has the privilege "SELECT_CATALOG_ROLE" and this role is the default role;

I created a function "FCGET_DDL_PART" within the scheme "DBLINK_USER" as shown below:

CREATE OR REPLACE FUNCTION DBLINK_USER.FCGET_DDL_PART (P_OBJECT_TYPE VARCHAR2,  P_NM_OBJECT VARCHAR2, P_NM_SQUEMA VARCHAR2, P_POS INTEGER DEFAULT 1) RETURN VARCHAR2 IS V_DDL CLOB;