BUG #2314: The Order changed?

The following bug has been logged online:

Bug reference: 2314
Logged by: L.Jumadi
Email address: j0e(at)telkom(dot)net
PostgreSQL version: 8.1.3
Operating system: SimplyMepis 3.4.3 with kernel 2.6.15.2
Description: The Order changed?
Details:

I have a table named test with field like this:
ocode varchar(8), code varchar(8) with primary key
at ocode.With data like this:
ocode code
'test' '-0'
'test' '-1'
'test' '1'
'test' '2'
I give the command in the psql like this:
SELECT * FROM test ORDER BY code;
the result is like this:
ocode code
test -0
test 1
test -1
test 2
When I use 8.0.1 version this command gives me result
like this
ocode code
test -0
test -1
test 1
test 2
The question is this a bug?or there is changes in the
way postgreSQL order the field? Thank's in advance