Are you using a 1.4 JDK? The addition of stackTrace & state to Thread is a JDK 1.5 addition View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3991699#3991699 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3991699