I upgraded from postgresql 8.4 to 9.2 and hibernate complains the following
WARN 02-26-13 07:25:51:198 PublishAcceptor.GridResourceLocation org.hibernate.cfg.SettingsFactory Could not obtain connection metadata
org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1225)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:80)
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:72)

Following are the details
1. Web application on Tomcat
2. Java platform
3. OS linux centOS
4. Upgraded from Postgres 8.4 to 9.2
5. Upgraded to latest JDBC 4 driver postgresql-9.2-1002.jdbc4.jar

I used pg_upgrade for the actual upgrade.
I have tried the following
1. ps -aux | grep postgres lists all my postgres processes with their expected ports
2. Telnet to localhost and port works fine
3. Listen address in postgresql.conf file is 'localhost'
4. Authentication method in pg_hba.conf file is 'trust'
5. psql -U <USER> -p <PORT> -d <DB> works fine
6. psql postgresql://<USER>@localhost:5432/<DB> works fine

I did not change any of the previous hibernate properties which worked fine with 8.4
From the exception it is clear that hibernate cannot get to the post master but I have no clue why.

Please let me know what I am missing here