pg_dump error - Permission denied

Dear friends,

I am working with Postgres 7.3.4 on RH Linux 7.3.

I could manage to take a backup using the following command and as the user 'postgres'.
$ pg_dump -h 192.168.2.51 -v -u -f /home/db_repository/test20031103.sql test

But while I try to execute the same command with the user 'kumar', it gives me the following error
>>
pg_dump: query to get data of sequence "clients_client_id_seq" failed: ERROR: clients_client_id_seq: permission denied
pg_dump: *** aborted because of error

But as the user 'kumar' I could manage to get the next value of the sequence with the following command
select nextval('test.clients_client_id_seq');

Previously, user 'postgres' is the owner of the database and I have changed that to 'kumar' via the following command
UPDATE pg_database SET datdba = 105 where datname = 'test';

Even though I am the owner of the sequence, why I am getting this error. Anybody could shed some light, pls.

Regards
Kumar