can't connect using the -host option

Dear All,

Strange behaviour....

I'm working in a TCL environment and use pg_connect to connect to pgsql
databases.  I want to move a suite of apps into production testing.  I need
to be able to run an app on any workstation, and connect to a database on
any workstation on our tcp-ip network.  For example, the development
database might be on one host, but the production and QA databases on
another.  And I might want to test any database interactively...

However, even if the database is ON my current workstation, I can ONLY
connnect with the command, "pg_connect dbName".  If I use the -host option,
I get the error:

Error: Connection to database failed
User Authentication failed

... strange indeed.  Suggestions on making this work?

Also, when I started up an identical database on a different workstation,
even with a different port, it caused my original database on my home
server to cease accepting connections.

All suggestions are welcome.  If I ask for help from Unix Admin, they'll
tell us that we have to migrate to one of their "supported" databases, such
as Sybase... something I 'd like to avoid!!

Cheers
Rob