As writed on postgre driver page you should use "JDBC4 Postgresql Driver, Version 9.1-901" because webratio and apache related version works on jdk 1.6.
From posgre web site:
- JDK 1.1 - JDBC 1. Note that with the 8.0 release JDBC 1 support has been removed, so look to update your JDK when you update your server.
- JDK 1.2, 1.3 - JDBC 2.
- JDK 1.3 + J2EE - JDBC 2 EE. This contains additional support for javax.sql classes.
- JDK 1.4, 1.5 - JDBC 3. This contains support for SSL and javax.sql, but does not require J2EE as it has been added to the J2SE release.
- JDK 1.6, 1.7 - JDBC4. Support for JDBC4 methods is not complete, but the majority of methods are implemented.
I've tried it on WebRatio and I've seen that webratio expect postgresql-9.jdbc3.jar! You can try to rename JDBC4 Postgresql Driver or download "JDBC3 Postgresql Driver, Version 9.1-901" but, in my opinion, this could be a lapse left when webratio was "updated" to jdk 1.6.
For me best way is rename JDBC4 Postgresql Driver