plugin2 knuddels.de chat applet doesn't start

The bug appears on GNU/Linux FF3 and Windows FF3/IE7.

The attempt to launch the chat applet (knuddels.de -> click 'over 20')
is not successfull, the start aborts.

It launches 2 applets, where the 1st is stopped right away,
and brings down the other one with the following exception ...

PERF: 473 us, dT 447 us :PluginMain - handleMessageStopApplet() - 1 - manager.stop() - START
PERF: 534 us, dT 61 us, user dT 534 us :Plugin2Manager - stop() - BEGIN
PERF: 586 us, dT 52 us :Plugin2Manager - stop() - stopLock - pre
network: Cache entry not found [url: http://chat.knuddels.de/knuddelsk89ya.jar, version: null]
PERF: 200693 us, dT 200107 us :Plugin2Manager - stop() - afterStopRunnable.run() - START
java.lang.Exception: PluginMain.unregisterApplet: 2 from sun.plugin2.applet.Applet2Manager@edf3f6, sun.plugin2.applet.Applet2Manager@edf3f
6
    at sun.plugin2.main.client.PluginMain.unregisterApplet(PluginMain.java:329)
    at sun.plugin2.main.client.PluginMain.access$1800(PluginMain.java:44)
    at sun.plugin2.main.client.PluginMain$4.run(PluginMain.java:1182)
    at sun.plugin2.applet.Plugin2Manager.stop(Plugin2Manager.java:541)
    at sun.plugin2.main.client.PluginMain.handleMessageStopApplet(PluginMain.java:1215)
    at sun.plugin2.main.client.PluginMain.mainLoop(PluginMain.java:421)
    at sun.plugin2.main.client.PluginMain.run(PluginMain.java:294)
    at sun.plugin2.main.client.PluginMain.main(PluginMain.java:1659)
PERF: 201274 us, dT 581 us, user dT 201274 us :PluginMain - unregisterApplet() - BEGIN
PERF: 201392 us, dT 118 us, user dT 118 us :PluginMain - unregisterApplet() - END
PERF: 201443 us, dT 51 us :Plugin2Manager - stop() - afterStopRunnable.run() - END
PERF: 201736 us, dT 293 us :Plugin2Manager - stop() - AWT disposal - post
PERF: 201797 us, dT 61 us, user dT 201797 us :Plugin2Manager - shutdownAppContext() - BEGIN
PERF: 201861 us, dT 64 us :Plugin2Manager - shutdownAppContext() - unregisterFromAppContext() - post
Applet2Manager executing destroyTGAndAC() for entry http://www.knuddels.de/
PERF: 201974 us, dT 113 us, user dT 201974 us :Plugin2Manager - destroyAppContext() - BEGIN
PERF: 222235 us, dT 20261 us :Plugin2Manager - destroyAppContext() - windowEnumerator - post
basic: Applet initialized
basic: Removed progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@11e0c13
java.lang.reflect.InvocationTargetException
    at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:116)
    at sun.plugin2.applet.Plugin2Manager.runOnEDT(Plugin2Manager.java:3028)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1338)
    at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable$3.run(Plugin2Manager.java:1341)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
Exception: java.lang.reflect.InvocationTargetException
Ignored exception: java.lang.reflect.InvocationTargetException
PERF: 236741 us, dT 14506 us :Plugin2Manager - destroyAppContext() - stopLock - post
PERF: 236846 us, dT 105 us :Plugin2Manager - destroyAppContext() - windows/displayable - post
PERF: 237230 us, dT 384 us :Plugin2Manager - destroyAppContext() - fac.dispose() - START
java.lang.NullPointerException
    at com.sun.deploy.ui.UIFactory.showErrorDialog(UIFactory.java:231)
    at com.sun.deploy.ui.UIFactory.showExceptionDialog(UIFactory.java:465)
    at com.sun.deploy.ui.UIFactory.showExceptionDialog(UIFactory.java:445)
    at com.sun.deploy.util.Trace.printException(Trace.java:464)
    at com.sun.deploy.util.Trace.printException(Trace.java:439)
    at com.sun.deploy.util.Trace.printException(Trace.java:412)
    at com.sun.deploy.util.Trace.printException(Trace.java:401)
    at sun.plugin2.applet.Plugin2Manager.showAppletException(Plugin2Manager.java:2959)
    at sun.plugin2.applet.Plugin2Manager.showAppletException(Plugin2Manager.java:2951)
    at sun.plugin2.applet.Plugin2Manager.runOnEDT(Plugin2Manager.java:3032)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1338)
    at java.lang.Thread.run(Thread.java:619)
basic: Applet made visible
basic: Skipped starting applet -- terminated abruptly
basic: Starting applet teardown
basic: Finished applet teardown