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_barfoobarsnackbarcrow_bar
(4 rows)

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

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

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