Cartesian product not correct

Hi

Given the sql below shouldn't I get the 3 records back?

create table t1 (attribute text);
insert into t1 values ('cars');
insert into t1 values ('trucks');
insert into t1 values ('bikes');

create table t2 (id serial, category text, attribute text, val integer);
insert into t2(category, attribute, val) values ('vehicle','cars', 100);

select t2.category, t1.attribute, 0 as val
from t2, t1
where t2.id in (
  select max(id)
  from t2
  group by category
);

PostgreSQL 8.4.0 on windows

Cheers
Angus