Timestamp Datatype Changing automatically to Timestamp without time zone

[Rajdeep Das <sendrajster(at)gmail(dot)com>]

Dear Sir/Madam,

This is important and I need your help here.

I have taken a dump of my database from the old version of pg viz.8.1, using
pg_dump command. In the db I have a table with a column of datatype
'timestamp'. Now, when I try to restore it on the new pg version 8.3, the
datatype of the column is getting altered to 'timestamp with no time zone'.
This change is causing my SQL to fail as TO_TIMESTAMP function is reporting
error.
Please suggest me the cause of this automatic datatype change. Also, tell me
how to make my TO_TIMESTAMP and other data functions work.

Thank You
Rajdeep