The onOpen event no longer fires when a menu popup is closed.

The following code works on version 5.0.11 and also on 6.0.0 but it does not work on 6.0.1:

index.zul:
<zk>
<window border="normal" title="hello" apply="pkg$.TestComposer">

<div>MenuPopup onOpen Event</div>
<div>Click the button below to open the menu - the onOpen event fires. Click away from the menu to close it, the onOpen event should fire again</div>

<button id="btn" label="Click me to popup dynamic menu" />
</window>
</zk>

TestComposer.java:

import org.zkoss.zk.ui.*;
import org.zkoss.zk.ui.event.*;
import org.zkoss.zk.ui.util.*;
import org.zkoss.zk.ui.ext.*;
import org.zkoss.zk.au.*;
import org.zkoss.zk.au.out.*;
import org.zkoss.zul.*;

public class TestComposer extends GenericForwardComposer{

public void doAfterCompose(Component comp) throws Exception

{ super.doAfterCompose(comp); }

public void onClick$btn(Event e) throws InterruptedException{

Menupopup contextMenu = new Menupopup();

contextMenu.addEventListener("onOpen", new EventListener() {
public void onEvent(Event evt) {
OpenEvent e = (OpenEvent) evt;
if (!e.isOpen()) {
try

{ Messagebox.show("Menu Closed..."); }

catch (Exception x){}
evt.getTarget().detach();

}
}

});

Menu reportMenu = new Menu("MyMenu");
contextMenu.appendChild(reportMenu);

contextMenu.setPage(e.getTarget().getPage());
contextMenu.open(20,20);
}
}