Known problem? Column mixup in sql-function

Hi,
I found a weired issue with a rather simple sql-function.
There are tables for projects, users and a m:n-relation between users
and projects where an user-id and a project-id say that this user has
acces to this project.
The function should filter all projects a user has access to.

This works nicely with a PG 8.4.8 on Windows but fails with a PG 8.4.0
on openSuse 11.1.
Well I know, OpenSuse 11.1 is out of support allread but I can't help it
for now.

On Suse the columns are mixed up.
The column names are in the same order as on windows but the data apears
in the wrong columns and some of the columns to the right show no data
at all.
I can run the query outside the function and it looks ok.
It seems that the "returns setof projects" doesn't work.
Is this a known problem?

CREATE OR REPLACE FUNCTION projects_with_access(integer)
RETURNS SETOF projects AS
$BODY$
SELECT projects.*
FROM projects
JOIN projectaccessrights USING ( project_id )
WHERE user_id = $1;
$BODY$