Time problem

Hi All,
I have installed postgres 7.1.3 as database.

For my application I have used timestamp as the datatype for date and time.

I am facing the following problem:

1) While inserting data, I do not have any trouble and the time taken is the
system time.
2) In the console when I select data it shows me the correct time.
3) BUT, when I am retrieving data from the sql query (code) and displaying
it, it is inexplicably ahead of the System time by exactly 30 mins.
4) I have tried setting the TIME ZONE variable to all possible combinations
as mentioned in the documentation. But even then if I ask the system to SHOW
TIME ZONE, it says "TIME ZONE IS UNKNOWN".
5) I have tried to find and set the environment variable, but again to no
avail.

I need help to sort this out, since it is throwing my otherwise sensible
application out of gear.

Regards
Jaya