sorting goofiness

I'm experiencing some goofiness with the order by clause on postgres.
I'm running the 7.2 install from redhat:

****
[hroberts(at)h2o h2o]$ rpm -q postgresql-server
postgresql-server-7.2-1PGDG
****

When I try to sort by a text column, I get odd results:

****
h2o_hroberts=# select ''''||foo||'''' as foo from bar order by foo;
foo
-----------------------
'a'
'a a'
'aaa'
'a b'
'ab '
'abb'
'a l'
'a l'
'alyxbqu lynscw gshi'
'a n'
'a n'
'an'
'a nkp'
'ann'
'a o'
'b'
'bb b'
'bbbb'
(18 rows)
****

"foo" is just a text field. The determination of whether a string with
a space at a given location should be sorted before a string with
non-space at the same location seems to depend on a number of variables
including the total length of the string and the character following the
space. In my elementary school career, I learned that a space should
always sort before a non-space.

Am I missing something here ?

-hal