Upgrade to Confluence 3.4.2 was successful on our test server but the same setup doesn't work in production.
It appears to start then shut itself down:
(from atlassian-confluence.log)
2012-11-12 14:06:02,367 INFO main com.atlassian.confluence.lifecycle init Confluence is ready to serve
2012-11-12 14:06:03,447 INFO main atlassian.plugin.manager.DefaultPluginManager shutdown Shutting down the plugin system
2012-11-12 14:06:05,969 INFO main com.atlassian.confluence.lifecycle destroy Shutting down long running task service
2012-11-12 14:06:06,060 INFO main com.atlassian.confluence.lifecycle contextDestroyed Stopping Confluence