Pro 3.0beta Failed to Run with PostgreSQL 8.0beta3

I installed JIRA Pro 3.0beta on Jetty and it runs fine, except it can't run with Confluence 1.2.2 as another webapp on the same Jetty 4.2.22 instance (http://jira.atlassian.com/browse/JRA-4802). So I have to switch back to Tomcat. Did everything according to install doc. Tried to bring it up the first time to run setup. Got the following exception. You can see "pg74.215.jdbc3.jar" is indeed loaded and I checked "org.postgresql.Driver" is there in it. But somehow this driver failed to load. The same database and driver runs perfectly for a Confluence 1.2.2 installation on the same Tomcat instance. What's wrong? Please help. Thanks!

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2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/osworkflow-17Aug2004.jar to /opt/jira/deployed-war/WEB-INF/lib/osworkflow-17Aug2004.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/pg74.215.jdbc3.jar to /opt/jira/deployed-war/WEB-INF/lib/pg74.215.jdbc3.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/picocontainer-1.0.jar to /opt/jira/deployed-war/WEB-INF/lib/picocontainer-1.0.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/propertyset-1.3.jar to /opt/jira/deployed-war/WEB-INF/lib/propertyset-1.3.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/quartz-1.0.7.jar to /opt/jira/deployed-war/WEB-INF/lib/quartz-1.0.7.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/seraph-0.7.4.jar to /opt/jira/deployed-war/WEB-INF/lib/seraph-0.7.4.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/sitemesh-2.0.2-020204dev.jar to /opt/jira/deployed-war/WEB-INF/lib/sitemesh-2.0.2-020204dev.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/statcvs-20040721-patched.jar to /opt/jira/deployed-war/WEB-INF/lib/statcvs-20040721-patched.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/velocity-1.4.jar to /opt/jira/deployed-war/WEB-INF/lib/velocity-1.4.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/webwork-1.4.jar to /opt/jira/deployed-war/WEB-INF/lib/webwork-1.4.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/webwork-pell-multipartrequest1.30rc1.jar to /opt/jira/deployed-war/WEB-INF/lib/webwork-pell-multipartrequest1.30rc1.jar
2004-10-09 17:25:13 WebappLoader[/jira]: Deploy JAR /WEB-INF/lib/xmlrpc-1.2-b1.jar to /opt/jira/deployed-war/WEB-INF/lib/xmlrpc-1.2-b1.jar
2004-10-09 17:25:13 PersistentManager[/jira]: Seeding random number generator class java.security.SecureRandom
2004-10-09 17:25:13 PersistentManager[/jira]: Seeding of random number generator has been completed
2004-10-09 17:25:13 PersistentManager[/jira]: No Store configured, persistence disabled
2004-10-09 17:25:16 StandardContext[/jira]: Exception sending context initialized event to listener instance of class com.atlassian.jira.upgrade.ConsistencyLauncher
com.opensymphony.module.propertyset.PropertyImplementationException: Unable to esablish a connection with the database. (Cannot load JDBC driver class 'org.postgresql.Driver')
at com.opensymphony.module.propertyset.ofbiz.OFBizPropertySet.getKeys(OFBizPropertySet.java:100)
at com.opensymphony.module.propertyset.AbstractPropertySet.getKeys(AbstractPropertySet.java:292)
at com.opensymphony.module.propertyset.PropertySetCloner.cloneProperties(PropertySetCloner.java:114)
at com.opensymphony.module.propertyset.PropertySetManager.clone(PropertySetManager.java:61)