Session management and performance issue

Hi,
I am getting error as

Jun 28, 2012 5:26:11 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/SarvatraMiddleware] registered the JDBC driver [oracle.jdbc.OracleDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.

Please help me to get out of this and know the cause for this.

I am also slow performance when running with sever on other PC but at localhost it is running fine.

Thanks

Vivek Ojha: Jun 28, 2012 5:26:11 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/SarvatraMiddleware] registered the JDBC driver [oracle.jdbc.OracleDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.

A quick Google search for "To prevent a memory leak, the JDBC Driver has been forcibly unregistered" gave more info on the problem, for instance this page.

That issue isn't specific to Vaadin, but has to do with the JDBC driver and the web container.

Cheers,
Bobby

What's odd to me is that we get this message, too, yet we have a ContextListener that does deregister the driver in the contextDestroyed() callback. But we just ignore it...