This is a JBoss bug. Class loading was done in the wrong manner, relying on an unintended side effect of the class loading mechanism, and when the behavior changed in Java 6, it broke a lot of software. What you see there is a failed attempt at loading the class for String[], not String. JBoss AS 5.0 is supposed to be free of these issues once it's finished. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4061612#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...