pg_catalog permission problem

I'm using Postgres 7.4. I have a database called tracking and user called
test5. From the Red Hat command line test5 can psql tracking and run:

SELECT * FROM Customers;

Not surprisingly, a list of customers is shown.

I have a Visual Basic application is accessing the same database. The same
user can open a connection to the same database. When the same query is run
the following error is thrown from Postgres:

permission denied for schema pg_catalog

With the connection to the database still open, I've run the foloowing query:

SHOW search_path;

And the following error message is returned:

permission denied for relation pg_type

Setting this user to usesuper=True in the pg_shadow table enables everything
to work correctly. But I obviously don't want to do that.

I've also tried:

GRANT ALL ON SCHEMA pg_catalog TO test5;
and
GRANT ALL ON SCHEMA pg_catalog TO PUBLIC;

and that doesn't seem to work.

Any ideas on where my permissions problem is? Is this something I missed in
the Postgres install? Could the Postgres process be running under an
inccorect user id?

I'd appreciate any help. Thanks...