PsqlODBC Error

I got "could not connect to remote socket(#1)" when I tried to export my
Access 97 database to postgresql 6.3

My config for datasource(psqlODBC) in control panel:
Database = student  #My database name in postgresql (Redhat 5.1)
Server = hostname.domainname.edu.my
User Name = rasyidi
Port = 5432 (default)
password = no password. (if I key in password also cannot connect)

option(Advanced)
datasource -- protocol = 6.3

In my redhat 5.1.
I createuser rasyidi
can create database
can create user.

using rasyidi, I createdb student and staff_info table with 4 fields:
Name,email,post,department(TEXT).
in pg_hba.conf, I add at the last line to allow all ip address in my place
can connect to the server:
host  all   xxx.xxx.xx.0   255.255.255.0  trust

thats all for my database server.
But I do not know the postmaster start with -i or not because I am using
rpm package that come with redhat 5.1.

My network environment.
Domain name server is on AIX server(building A) and redhat 5.1 is on
another server(Building B)
Have subnet mask.

Access 97
got 4 fields = name,email,post,department - no primary key
with some data inside the table.
database name simpledb and staff_info table.

Can some one help me to make the connection.

Thanks...