I, too, have run into this problem. As it turned out, we were distributing our Oracle JDBC driver .jar with the web application and when we removed it and placed it into server/[default]/lib the problem went away. I have *no* idea why this worked, but we are sticking with it as I have no time to become an expert on JBoss classloading, etc. (We also bumped up our PermGenSpace to 256M, but this only temporarily solved the problem. Removing the JDBC .jar fixed it "permanently".) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4089079#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...