There is some info here: http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration I don't have much experience in this since I haven't had that many classloading problems but following seam-gen example, try putting in the ear META-INF a jboss-app.xml with | <?xml version="1.0" encoding="ISO-8859-1"?> | <!DOCTYPE jboss-app | PUBLIC "-//JBoss//DTD J2EE Application 4.2//EN" | "http://www.jboss.org/j2ee/dtd/jboss-app_4_2.dtd"> | | <jboss-app> | <loader-repository>seam.jboss.org:loader=unique</loader-repository> | </jboss-app> | and something other unique in the other ear. It's a long shot since one would think that normally one ear couldn't possible have effect on the other but experience shows otherwise as you have experienced... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4123188#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...