Strange behaviour of RULE (selecting last inserted ID of 'sequenced' column)

Is this a bug?

test=> create sequence strange_seq;
CREATE SEQUENCE
test=> create table strange(id integer not null default
nextval('strange_seq') primary key, data text);
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index
"strange_pkey" for table "strange"
CREATE TABLE
test=> create rule strange_rule as on insert to strange do select new.id as id;
CREATE RULE
test=> insert into strange(data) values('adas');
id
----
2
(1 row)

test=> select * from strange;
id | data
----+------
1 | adas
(1 row)

test=> insert into strange(data) values('adas');
id
----
4
(1 row)

test=> insert into strange(data) values('adas');
id
----
6
(1 row)

test=> select * from strange;
id | data
----+------
1 | adas
3 | adas
5 | adas
(3 rows)

--
Best regards,
Nikolay