java.lang.ClassCastException: org.netbeans.modules.kenai.collab.chat.ContactList cannot be cast to org.netbeans.modules.kenai.collab.chat.ChatPanel
        at org.netbeans.modules.kenai.collab.chat.ChatTopComponent$5.propertyChange(ChatTopComponent.java:183)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:347)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at java.awt.Component.firePropertyChange(Component.java:8213)
        at org.openide.awt.CloseButtonTabbedPane.fireCloseRequest(CloseButtonTabbedPane.java:472)
        at org.openide.awt.CloseButtonTabbedPane.access$200(CloseButtonTabbedPane.java:90)
        at org.openide.awt.CloseButtonTabbedPane$ButtonTab$TabButton.actionPerformed(CloseButtonTabbedPane.java:796)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6348)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6113)
        at java.awt.Container.processEvent(Container.java:2085)
        at java.awt.Component.dispatchEventImpl(Component.java:4714)
        at java.awt.Container.dispatchEventImpl(Container.java:2143)
        at java.awt.Component.dispatchEvent(Component.java:4544)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4618)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4282)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4212)
        at java.awt.Container.dispatchEventImpl(Container.java:2129)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4544)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:117)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)