We are getting "No database found on host" during install.

We have set up Postgresql carefully, with all the required roles and databases and are in screen 3 / Cluster setup.  We are using the fqn of the server (which is the same server that the Manager is running on btw, is that an issue?).  We have selected 'Postgresql' in the pick list, and the db name 'amon' and the user name 'amon' and password.  We have done a 'sudo service postgresql status' and see the server is running.  We have also done a 'sudo service postgresql restart'.  We have manually connected to psql and checked that the role and the database exist.  We have checked netstat -an for the port listening (5432) and confirmed that the database is configured for that port.  Firewall is off.

Despite all this we are getting "No database found on host".  Is there an installation log file that might tell us more?  Are there any troubleshooting tips or common causes for this?

Thanks.