order by when using cursors

Hi!

I did some experiments with cursors and found that my data doesn't get
sorted by the "order by"-statement.

Here is what I did:

----------------

CREATE TABLE ta (
a integer NOT NULL,
b integer NOT NULL
);

insert into ta values(3,1);
insert into ta values(1,2);
insert into ta values(4,3);
insert into ta values(2,4);

CREATE OR REPLACE FUNCTION testcur( OUT a integer, OUT b integer )
RETURNS SETOF RECORD AS $$
DECLARE
cur refcursor;
BEGIN
OPEN cur FOR SELECT * FROM ta ORDER BY a DESC;
LOOP
FETCH cur INTO a,b;
IF not found THEN
exit;
ELSE
RETURN NEXT;
END IF;
END LOOP;
CLOSE cur;
END;
$$ LANGUAGE 'PLPGSQL' ;

SELECT * FROM testcur();

----------------

As the result I get:

3 1
1 2
4 3
2 4

Which is not ordered by column a!?

Is this intended?
Am I doing something wrong?

I'm using Postgresql 8.3.1

Patrick