Quitting frame sometimes causes NullPointerException on Solaris OpenWindows

Start the BigEventTest application
(in /usr/sqe/workspaces/jck11-tests-int/tests/api/java_awt/interactive/event).

Click on the "Menus & Windows" button.
After the window, frame, and dialog have come up, click the right button
on the top left corner of the frame, and select Quit from the menu that
comes up.

This sometimes causes a NullPointerException:
mouseMoved: java.awt.event.MouseEvent[MOUSE_MOVED,(17,89),mods=0,clickCount=0] on frame3
mouseExited: java.awt.event.MouseEvent[MOUSE_EXITED,(19,49),mods=0,clickCount=0] on frame3
windowDeactivated: java.awt.event.WindowEvent[WINDOW_DEACTIVATED] on frame3
focusLost: java.awt.event.FocusEvent[FOCUS_LOST,temporary] on frame3
focusGained: java.awt.event.FocusEvent[FOCUS_GAINED,permanent] on frame3
focusLost: java.awt.event.FocusEvent[FOCUS_LOST,permanent] on frame3
focusGained: java.awt.event.FocusEvent[FOCUS_GAINED,permanent] on frame3
windowClosing: java.awt.event.WindowEvent[WINDOW_CLOSING] on frame3
windowClosed: java.awt.event.WindowEvent[WINDOW_CLOSED] on dialog2
windowClosed: java.awt.event.WindowEvent[WINDOW_CLOSED] on win9
windowClosed: java.awt.event.WindowEvent[WINDOW_CLOSED] on frame3
Exception occurred during event handling:
java.lang.NullPointerException
        at java.awt.Container.dispatchEventImpl(Container.java)
        at java.awt.Window.dispatchEventImpl(Window.java)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java)
 
        sun.awt.motif.MChoicePeer.initialize(MChoicePeer.java:42)
        sun.awt.motif.MComponentPeer.<init>(MComponentPeer.java:111)
        sun.awt.motif.MChoicePeer.<init>(MChoicePeer.java:46)
        sun.awt.motif.MToolkit.createChoice(MToolkit.java:144)
        java.awt.Choice.addNotify(Choice.java)
        java.awt.Container.addImpl(Container.java)
        java.awt.Container.add(Container.java)
        BigEventTest.addToComponentPanel(BigEventTest.java:605)
        BigEventTest.loadComponents4(BigEventTest.java:401)
        BigEventTest.actionPerformed(BigEventTest.java:134)
        java.awt.Button.processActionEvent(Button.java)
        java.awt.Button.processEvent(Button.java)
        java.awt.Component.dispatchEventImpl(Component.java)
        java.awt.EventDispatchThread.run(EventDispatchThread.java)