Connect via odbc from Windows to Linux

I am trying to set up an odbc connection from Windows 2000 to Postgresql running on Linux (CentOS 4.7).

I have the appropriate Postgresql jdbc driver on the windows box as well as the hosts file with the linux host.
Postgresql.confhas listen_addresses = '*'. The port is the same on both ends. 

Trying various configurations with the odbc datasource administrator, the most friendly response I can get from a test
isthat the connected party/host failed to respond ("properly after a period of time" in the case of the 'party'). 

I do have portsentry running on the linux host but the windows box is not blocked.

I'm afraid there must be a simple solution but I can't figure out what it is. Where should I look?

TIA,
Bruce Hyatt