CURRENT_DATE and CURRENT_TIME return incorrect values

I have a table with these columns:

   order_date      date                    DEFAULT CURRENT_DATE
   order_time      time with time zone     DEFAULT CURRENT_TIME
   setup_date      date
   last_update     date                    DEFAULT CURRENT_DATE

The order_date and last_update should always be identical because I let
pgsql fill in those fields when a new row is added.  Additionally,
setup_date should be identical as well, because my application just
queries the server time (same exact server as pgsql is running on).

However today I noticed something strange:  a row was added with these
values:

   order_date |     order_time     | setup_date | last_update
   -----------+--------------------+------------+------------
   2003-05-26 | 02:22:00.166015-04 | 2003-05-28 | 2003-05-26

Which is very odd because a few minutes later I ran a manual query that
returned this:

   dev=> SELECT current_date, current_time;
      date    |       timetz
   -----------+--------------------
   2003-05-28 | 13:19:39.189404-04

I also checked my apache log files to make sure that the server hadn't
skipped a few days for some reason...  But that wasn't the case, and my
logs show hits for the 26th, 27th and 28th, as it should be.

I then went back to my application and made it create a new record.  The
following row was created:

   order_date |     order_time     | setup_date | last_update
   -----------+--------------------+------------+------------
   2003-05-28 | 13:25:12.126979-04 | 2003-05-28 |  2003-05-28

What you may find interesting is that my DB had been mostly dormant for
the past several days.  In other words, only a few SELECT queries had
been executed, and no INSERT, UPDATE, DELETE or VACUUM operations had
been run.  I have no idea if this is significant or not...

My environment is:

pgsql 7.3.2
Debian/Linux 3.0 (i386)
/etc/timezone is 'US/Eastern'
libdbi-perl 1.21-2
libdbd-pg-perl 1.01-3

No defaults in postgresql.conf were changed except for
'unix_socket_directory'.  The Locale is set to 'C'.

I noticed that there are several entries in the HISTORY file for pgsql
7.3.3 that deal with dates and times.  Would upgrading fix my problem,
or is this something entirely different?