Error when creating table with boolean data type

I get an "Error: relation "boolean" does not exist when attempting to create
a table with columns of data type boolean. I using PostgreSQL 8.3.6 and the
docs say that it supports boolean data type and even show some create table
examples similar to mine.

Sorry for such a newbie question but it's so simple that I'm stumped.

Here's the terminal session:
quasar=# create table flags (
plate integer,
mjd integer,
fiber integer,
redshift real,
class varchar(20),
core boolean,
bonus boolean,
midz boolean,
lohiz boolean,
neural boolean,
ukidds boolean,
kde boolean,
like boolean,
first boolean,
umag real,
gmag real,
rmag real,
imag real,
zmag real,
visual varchar(20));
ERROR: relation "boolean" does not exist

Thanks.