Explain returns extremely high cost

Hi!

I have a database just recreated from scratch with SQL script.
(My PostgreSQL version is 8.1.3).
All of the tables are pretty empty, but that's what I've got with explain:

EXPLAIN SELECT * FROM account;
QUERY PLAN
------------------------------------------------------------------------
Seq Scan on account (cost=100000000.00..100000001.05 rows=5 width=41)

This is what I have in the table:

SELECT * FROM account;
obj_id | login | password | client_id | service_id | type_id | state_id
---------+---------+-------------+-----------+------------+---------+----------
1000513 | root | _system____ | 1000471 | 1000486 | 1000113 | 1000209
1000548 | root | _system____ | 1000472 | 1000536 | 1000113 | 1000209
1000550 | root | _system____ | 1000475 | 1000534 | 1000113 | 1000209
1000552 | sol | _sol | 1000472 | 1000536 | 1000113 | 1000209
1000554 | seregik | _seregik | 1000475 | 1000534 | 1000113 | 1000209
(5 rows)
Time: 1.346 ms

For other tables I have more or less the same high costs.

I've done VACUUM ANALYZE. This is what I have in pg_class table:

SELECT relpages,reltuples FROM pg_class WHERE relname='account';
relpages | reltuples
----------+-----------
1 | 5

Why the costs are so high? Is it a bug?
Thanks in advance for any suggestions!
Regards, Andrii