As of JDK 7 b37.
Please consider the following sequence:

    EventClient eventclient = new EventClient(getClient());
    NotificationListener listener = new SimpleListener();
    ObjectName pattern = new ObjectName("*:*");
    RankFilter filter = new RankFilter(discardedNotificationRank);
    // SUBSCRIBE WITH FILTER AND HANDBACK
    eventclient.subscribe(pattern, listener, filter, pattern);
    // UNSUBSCRIBE WITH SAME NAME AND PATTERN
    eventclient.unsubscribe(pattern, listener);

You get:

javax.management.ListenerNotFoundException
at javax.management.event.EventClient.getMatchedListenerInfo(EventClient.java:817)
at javax.management.event.EventClient.unsubscribe(EventClient.java:460)
at javasoft.sqe.jmx.test.functional.EventClientTest2.run(EventClientTest2.java:125)
at javasoft.sqe.jmx.share.TestStarter.<init>(TestStarter.java:28)
at javasoft.sqe.jmx.share.TestStarter.main(TestStarter.java:79)

EventConsumer.unsubscribe() javadoc says:

ListenerNotFoundException - The given listener was not subscribed to the given name.

The call to getMatchedListenerInfo() in the stack seems to say you can unsubscribe only if ListenerInfo matches, which isn't what the javadoc says.
Do I miss something there ?