well, I believe this matrix is for the server side. I assume that client Java version is a different story. We have upgraded to jBoss 4.04 from 3.2.3 but we still have some old client which must run on Java 1.3. I was assuming that version of client JVM is not tightly linked to the version of the server/server JVM. Probably I was wrong? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3959029#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...