ERROR: "foo_type" is a composite type

Hi all,
I'm experiencing problem with Postgresql 7.4Beta 3,
the following function is working in Postgres 7.3.X and
if I remember well also in 7.4beta2:

CREATE TYPE foo_type AS (a INTEGER);

CREATE OR REPLACE FUNCTION foo ( )
RETURNS SETOF foo_type AS'
DECLARE
my_var foo_type%rowtype;
BEGIN

FOR my_var IN
SELECT 2
LOOP
RETURN NEXT my_var;
END LOOP;

RETURN;

END;
' LANGUAGE 'plpgsql';

now I obtain:

test=# select * from foo();
ERROR: "foo_type" is a composite type
CONTEXT: compile of PL/pgSQL function "foo" near line 2

is the intended behaviour ?

Regards
Gaetano Mendola