Can't create DSN using SSPI authentication WinXP to WinXP

I have PostgreSQL 8.3.1 w32 running on Windows XP sp2 server.
I want to authenticate using sspi for my Windows XP clients (domained) but while creating a DSN, I get an "authentication method 9 not supported" error message. However, connecting with the pgAdmin III works fine.
Here is a screenshot of the error message on the client while trying to create a DSN:
http://pages.suddenlink.net/lt1/scnshot.jpg
The error message dialog box pops up after clicking the Test button.

If I change the entry in the pg_hba.conf file to from "sspi" to "trust", I can create the DSN with no problem. But, using trust for multiple users is not secure enough. I am using the latest psqlODBC verson (8.03.01.00).

I am not a programmer so I need to know if there is an easy fix for this.
Can anyone help me?

Roger