Postgre: 8.0.1 Create Table insde a function gives strange error at execution time

Code within a function is like this:
SELECT 1
INTO x
FROM pg_tables
where tablename = 'globals_pac_adressarten'
and tableowner = user;
IF (NOT FOUND) THEN
CREATE TEMPORARY TABLE globals_pac_adressarten
(INT_ALIAS_NAME VARCHAR(12) NOT NULL
,KOMMUNIKATION SMALLINT NOT NULL
,POSTALISCH SMALLINT NOT NULL
)
WITHOUT OIDS
ON COMMIT PRESERVE ROWS;
END IF;

When executing following errors are reported:

ERROR: syntax error at or near "$1" bei Zeichen 87
ANFRAGE: CREATE TEMPORARY TABLE globals_pac_adressarten (INT_ALIAS_NAME
VARCHAR(12) NOT NULL , $1 SMALLINT NOT NULL ,
$2 SMALLINT NOT NULL ) WITHOUT OIDS ON COMMIT PRESERVE ROWS
KONTEXT: PL/pgSQL function "padr_insert_address" line 142 at SQL statement
SQL statement "SELECT padr_insert_address('pCursor','1','1','xxx','0')"
PL/pgSQL function "test" line 6 at select into variables
ZEILE 1: ...dressarten (INT_ALIAS_NAME VARCHAR(12) NOT NULL , $1 SMALLI...

Would anybody know where those $1 and $2 come from?
If I run the "CREATE" under psql it's working OK;
Help appreciated..

Franz Stuetzle

Schertlinstr. 11-144
D-86159 Augsburg