BUG #2599: AM/PM doesn't work in to_timestamp in the middle of a string

The following bug has been logged online:

Bug reference:      2599
Logged by:          Josh Tolley
Email address:      eggyknap@gmail.com
PostgreSQL version: 8.1.4
Operating system:   Fedora Core 5
Description:        AM/PM doesn't work in to_timestamp in the middle of a
string
Details:

eggyknap=# select to_timestamp('30 Aug 06:01:03.223 PM 2006', 'DD Mon
HH:MI:SS.MS AM YYYY'), to_timestamp('30 Aug 2006 06:01:03.223 PM', 'DD Mon
YYYY HH:MI:SS.MS AM');
       to_timestamp        |        to_timestamp
---------------------------+----------------------------
 0001-08-30 18:01:03-08 BC | 2006-08-30 18:01:03.223-06

This appears to happen when AM/PM isn't the last element in the string.