Hi I have a problem.... could it be something really obvious?

the following code snippet:

...
Object o = new Object();
// or alternatively, Object o = new String("blah");
// or String o = new String("blah");
connector.addNotificationListener(...., o);

throws the following exception:
java.lang.ClassCastException: org.jboss.jmx.server.ObjectHandler

If I pass null as the handback object, everything works fine, and all invocations/notifications work beautifully.

Anything I am missing?

(jboss 2.4.6)

Thanks for your earliest help!