log timestamp since daylight saving time

Hi all -

Ever since daylight savings time, I've noticed that the timestamp in the
log files on 2 of our many postgres servers (version 8.4.5) did not
update.  It's still 1 hour behind.  The settings are all default (see
below) on all the servers.

# - Locale and Formatting -

datestyle = 'iso, mdy'
#intervalstyle = 'postgres'
#timezone = unknown                     # actually, defaults to TZ
environment
                                         # setting
#timezone_abbreviations = 'Default'     # Select the set of available
time zone
                                         # abbreviations.  Currently,
there are
                                         #   Default
                                         #   Australia
                                         #   India
                                         # You can create your own file in
                                         # share/timezonesets/.
#extra_float_digits = 0                 # min -15, max 2
#client_encoding = sql_ascii            # actually, defaults to database
                                         # encoding


I've also checked the timezone through psql - for the 2 incorrect
servers I get

postgres=# show timezone;
  TimeZone
----------
  EST5EDT
(1 row)

For the correct servers, I get.....

postgres=# show timezone;
   TimeZone
------------
  US/Eastern
(1 row)

postgres=#


How do you go about correcting this??

thanks!
Maria Wilson
NASA/Langley Research Center
Hampton, Virginia 23681