In MDI mode, have the Source Editor open.  close it.  Press Ctrl-3.  The 
following exception is thrown:

Mon Jun 04 13:50:26 EDT 2001: java.lang.NullPointerException: Posted StackTrace
Annotation: Exception occurred in Request Processor
org.openide.util.RequestProcessor$Holder: Posted StackTrace(task 
org.netbeans.core.ModuleActions$1@93b3c [0, 1, -1])
        at org.openide.util.RequestProcessor$Task.createHolder
(RequestProcessor.java:322)
        at org.openide.util.RequestProcessor.post(RequestProcessor.java:100)
        at org.openide.util.RequestProcessor.post(RequestProcessor.java:73)
        at org.netbeans.core.ModuleActions.invokeAction(ModuleActions.java:89)
        at org.openide.awt.Actions$ButtonBridge.actionPerformed
(Actions.java:351)
        at javax.swing.AbstractButton.fireActionPerformed
(AbstractButton.java:1450)
        at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed
(AbstractButton.java:1504)
        at javax.swing.DefaultButtonModel.fireActionPerformed
(DefaultButtonModel.java:378)
        at javax.swing.DefaultButtonModel.setPressed
(DefaultButtonModel.java:250)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:279)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:259)
        at javax.swing.plaf.basic.BasicMenuItemUI$ClickAction.actionPerformed
(BasicMenuItemUI.java:1007)
        at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1384)
        at javax.swing.JComponent.processKeyBinding(JComponent.java:2078)
        at javax.swing.JMenuBar.processBindingForKeyStrokeRecursive
(JMenuBar.java:666)
        at javax.swing.JMenuBar.processBindingForKeyStrokeRecursive
(JMenuBar.java:678)
        at javax.swing.JMenuBar.processKeyBinding(JMenuBar.java:648)
        at javax.swing.KeyboardManager.fireBinding(KeyboardManager.java:252)
        at javax.swing.KeyboardManager.fireKeyboardAction
(KeyboardManager.java:239)
        at javax.swing.JComponent.processKeyBindingsForAllComponents
(JComponent.java:2145)
        at javax.swing.JComponent.processKeyBindings(JComponent.java:2138)
        at javax.swing.JComponent.processKeyEvent(JComponent.java:2041)
        at java.awt.Component.processEvent(Component.java:3553)
        at java.awt.Container.processEvent(Container.java:1164)
        at java.awt.Component.dispatchEventImpl(Component.java:2593)
        at java.awt.Container.dispatchEventImpl(Container.java:1213)
        at java.awt.Component.dispatchEvent(Component.java:2497)
        at java.awt.LightweightDispatcher.processKeyEvent(Container.java:2155)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2135)
        at java.awt.Container.dispatchEventImpl(Container.java:1200)
        at java.awt.Window.dispatchEventImpl(Window.java:914)
        at java.awt.Component.dispatchEvent(Component.java:2497)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:339)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy
(EventDispatchThread.java:131)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy
(EventDispatchThread.java:98)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)
 
Mon Jun 04 13:50:26 EDT 2001: java.lang.NullPointerException: null
java.lang.NullPointerException
        at org.netbeans.core.actions.EditorViewAction.performAction
(EditorViewAction.java:74)
        at org.openide.util.actions.CallableSystemAction.actionPerformed
(CallableSystemAction.java:66)
        at org.netbeans.core.ModuleActions$1.run(ModuleActions.java:76)
        at org.openide.util.Task.run(Task.java:124)
[catch] at org.openide.util.RequestProcessor$ProcessorThread.run
(RequestProcessor.java:626)