Using the example persistence XMBean provided with JBoss 4.0.4 (persistence-service.sar), I have set the attribute SomeNullObject to a custom Serializable class (that happens to be a JavaBean). Serialization/persistence works when I set this method via a remote JMX client. However, when I restart JBoss, it complains that this class can not be found (but this class is in the SAR and it found it when it serialized just fine). A couple of other notes: * If we use the typical types of String, etc (apparently anything in the JDK), this problem does not happen. * If we place our class in the lib directory instead of the SAR, we have the same problem. Has anyone tried this, or does anyone have any suggestions? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3958226#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...