ODBC and Postgres 7

My goal is to set up Postgres 7 on Red Hat 6.2 and access it via ODBC from an NT machine.

I've set up PostgreSQL and it seems to be working. I can create the test database and manipulate it.

I created a pg_hba.conf file in /usr/lib/pgsql using the pg_hba.conf.sample file as a starting point. I added a line that looks like this

host all 1.2.3.4 255.255.255.0 trust

where 1.2.3.4 is the IP of my NT machine. I set up the ODBC driver and I can do a query but get the response

{error} STATE=28000, CODE=210, MSG=No pg_hba.conf entry for host 1.2.3.4, user skippy, database test

What have I missed? I thought the "all" took care of all users from 1.2.3.4.

Thanks in advance,

John