XP Excel with PostgreSQL on Linux?

I am trying to link Microsoft Excel on a Dell running XP to a PostgreSQL
database on a Linux box.
I've setup the DBN (ODBC) in AdminSettings--> Data Sources

And I can go into Excel at go through all the Data Source setup
and test the connection (it is fine) BUT I receive 'Unable to obtain
list of tables from data source'
What other information besides the username and password do I need?

Do I need to configure the server in some way to allow upload of this
information?
Maybe the server firewall is setup to not allow this?
Maybe I need to setup a UDL?

Although I can get to that same port using a Tomcat application.

Any help is appreciated.

Thanks,

Kelsey