I have tried with JDK 1.5.0 update 13 and I have the same problem at startup. But with JDK 1.6.0 update 2 => NO ERROR ON STARTUP !!! But as i'm using jbossws, I have on error when accessing my webservice. This is a resolved bug between jbossweb and JDK 1.6.0. So, i must use at least jbossweb 2.0.0. And also... JDK 1.6.0 is not certified for JBoss 4.2.1... So, anyone has another solution to avoid using JDK 1.6.0 ? Thanks, Olv View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4091101#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...