Permission denied for relation pg_database , one role has problem

And many others errors when xsome user connect to database x, schema
xxx. PG 8.4.

Problems started about same time as search_path has SET.
search_path has reset, but did'nt help.

ALTER DATABASE x SET search_path=some, public;
-- xxx wasn't in that list
ALTER DATABASE x RESET search_path; - has done

Only one group has this priviledge problem, xgroup.

pg_log after tried to connect:
2012-08-25 11:39:36 EEST ERROR: permission denied for relation pg_database
2012-08-25 11:39:36 EEST STATEMENT: SET DateStyle=ISO;
SELECT oid, pg_encoding_to_char(encoding) AS encoding, datlastsysoid
FROM pg_database WHERE oid = 16395

role xuser has done:
CREATE ROLE xuser LOGIN
ENCRYPTED PASSWORD 'some...'
NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;
ALTER ROLE xuser SET search_path=xxx;
GRANT xgroup TO xuser;

And xgroup has done:

CREATE ROLE xgroup
NOSUPERUSER NOINHERIT NOCREATEDB NOCREATEROLE;
COMMENT ON ROLE xgroup IS 'X Group';

Schema xxx has done:
CREATE SCHEMA xxx
AUTHORIZATION postgres;

GRANT ALL ON SCHEMA xxx TO postgres;
GRANT USAGE ON SCHEMA xxx TO xgroup;

Schema xxx include some views to public.tables and some own tables.

Views:
CREATE OR REPLACE VIEW
SELECT * FROM product;
ALTER TABLE xxx.product
OWNER TO postgres;
GRANT ALL ON TABLE xxx.product TO postgres;
GRANT SELECT ON TABLE xxx.product TO xgroup;

Own tables:
CREATE TABLE xxx.mytable
(
stamp timestamp without time zone NOT NULL
)
WITH (
OIDS=FALSE
);
ALTER TABLE xxx.mytable
OWNER TO postgres;
GRANT ALL ON TABLE xxx.mytable TO postgres;
GRANT SELECT, UPDATE, INSERT, DELETE ON TABLE xxx.mytable TO xgroup;

Something interesting happened when search_path has set ?
Is this some kind of catalog priviledge problem ?

-jukka-