Search for underscore w/ LIKE

How do I use LIKE to search for strings with an underscore? The
documentation (well, Bruce's book) says to use 2 underscores (__) but it
doesn't work. For example:

create table liketest (
somestr varchar(50)
);

insert into liketest values ('foo_bar');
insert into liketest values ('foobar');
insert into liketest values ('snackbar');
insert into liketest values ('crow_bar');

-- I want to select strings with "_bar"
select * from liketest where somestr like '%_bar';
somestr
----------
foo_bar
foobar
snackbar
crow_bar
(4 rows)

-- Using double underscore doesn't work either
select * from liketest where somestr like '%__bar';
somestr
----------
foo_bar
foobar
snackbar
crow_bar
(4 rows)

-- Escaping w/ backslash doesn't work
select * from liketest where somestr like '%\_bar';
somestr
----------
foo_bar
foobar
snackbar
crow_bar
(4 rows)

Brian
--
Brian Baquiran <brianb(at)edsamail(dot)com>
http://www.baquiran.com/ AIM: bbaquiran
Work: (632)7182222 Home: (632)9227123