Simple:
1) Create a gridbag.
2) Add a Choice control to it.
3) At runtime you get the segmentation fault shown below:

CODE TO REPRODUCE:

******* QuickTest.html *************************************************

<applet code="QuickTest" width=200 height=50> </applet>

******* QuickTest.java *************************************************

import java.awt.*;
import java.lang.*;
import java.applet.*;

public class QuickTest extends Applet {

  Choice testChoice;
  Frame theFrame;

  public void init() {

    theFrame = new Frame();

    Panel topPanel = new Panel();

    GridBagLayout gridbag = new GridBagLayout();
    GridBagConstraints gbC = new GridBagConstraints();
    Component component = null;

    topPanel.setLayout(gridbag);

    // Backup id Choice
    clear_constraints(gbC);
    gbC.gridx = 0;
    gbC.gridy = 0;
    gbC.anchor = GridBagConstraints.SOUTHWEST;
    testChoice = new Choice();
    component = testChoice;
    // VVVVVVVV Commenting out this line causes core dump VVVVVVV
    // ((Choice)component).addItem("This is a test");
    // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    gridbag.setConstraints(component, gbC);
    topPanel.add(component);
    System.out.println("DEBUG - added...");

    theFrame.add("Center", topPanel);
    theFrame.pack();
    theFrame.resize(200,200);
    theFrame.show();
  }

    public void clear_constraints(GridBagConstraints gbConstraints) {
      gbConstraints.gridx = -1;
      gbConstraints.gridy = -1;
      gbConstraints.gridwidth = 1;
      gbConstraints.gridheight = 1;
      gbConstraints.weightx = 0;
      gbConstraints.weighty = 0;
      gbConstraints.fill = GridBagConstraints.NONE;
      gbConstraints.anchor = GridBagConstraints.CENTER;
    }
}


******* SEGMENTATION VIOLATION: ********************************************

SIGSEGV 11* segmentation violation
    si_signo [11]: SIGSEGV 11* segmentation violation
    si_errno [0]: Error 0
    si_code [1]: SEGV_ACCERR [addr: 0xfffffffc]

        stackbase=EF461000, stackpointer=EF45FE68

Full thread dump:
    "Screen Updater" (TID:0xee3033a0, sys_thread_t:0xef0d0de0) prio=4
        java.lang.Object.wait(Object.java)
        sun.awt.ScreenUpdater.nextEntry(ScreenUpdater.java:75)
        sun.awt.ScreenUpdater.run(ScreenUpdater.java:95)
    "AWT-Motif" (TID:0xee303030, sys_thread_t:0xef100de0) prio=5
        java.awt.Window.postEvent(Window.java:169)
        sun.awt.motif.MFramePeer.handleMoved(MFramePeer.java:124)
        java.lang.Thread.run(Thread.java)
    "AWT-Input" (TID:0xee303008, sys_thread_t:0xef130de0) prio=5
    "thread applet-QuickTest" (TID:0xee302e48, sys_thread_t:0xef460de0) prio=6 *current thread*
        sun.awt.motif.MChoicePeer.initialize(MChoicePeer.java:35)
        sun.awt.motif.MComponentPeer.<init>(MComponentPeer.java:87)
        sun.awt.motif.MChoicePeer.<init>(MChoicePeer.java:40)
        sun.awt.motif.MToolkit.createChoice(MToolkit.java:81)
        java.awt.Choice.addNotify(Choice.java:55)
        java.awt.Container.addNotify(Container.java:363)
        java.awt.Panel.addNotify(Panel.java:47)
        java.awt.Container.addNotify(Container.java:363)
        java.awt.Window.addNotify(Window.java:72)
        java.awt.Frame.addNotify(Frame.java:87)
        java.awt.Window.pack(Window.java:83)
        QuickTest.init(QuickTest.java:38)
        sun.applet.AppletPanel.run(AppletPanel.java:243)
        java.lang.Thread.run(Thread.java)
    "Finalizer thread" (TID:0xee3003b0, sys_thread_t:0xef490de0) prio=1
    "Async Garbage Collector" (TID:0xee300368, sys_thread_t:0xef4c0de0) prio=1
    "Idle thread" (TID:0xee300320, sys_thread_t:0xef4f0de0) prio=0
    "clock handler" (TID:0xee3001f8, sys_thread_t:0xef5b0de0) prio=11
    "main" (TID:0xee3000a0, sys_thread_t:0x83f68) prio=5
Monitor Cache Dump:
    unknown key (key=0xef4c0de0): unowned
        Waiting to be notified:
            "Async Garbage Collector"
    sun.awt.motif.MToolkit@EE302FF0/EE33F7E8 (key=0xee302ff0): monitor owner: "thread applet-QuickTest"
        Waiting to be notified:
            "AWT-Input"
    java.awt.Frame@EE303778/EE341708 (key=0xee303778): monitor owner: "thread applet-QuickTest"
    java.awt.Choice@EE303808/EE341B40 (key=0xee303808): monitor owner: "thread applet-QuickTest"
    java.awt.Panel@EE303790/EE3417A8 (key=0xee303790): monitor owner: "thread applet-QuickTest"
    sun.awt.motif.MFramePeer@EE3030A8/EE33FA60 (key=0xee3030a8): monitor owner: "AWT-Motif"
    sun.awt.ScreenUpdater@EE3033A0/EE3401F8 (key=0xee3033a0): unowned
        Waiting to be notified:
            "Screen Updater"
Registered Monitor Dump:
    unowned
        Waiting to be notified:
            Finalize me queue lock: "Finalizer thread"
    unowned
        Waiting to be notified:
            Thread queue lock: "main"
    unowned
    unowned
    unowned
    unowned
    unowned
    unowned
    unowned
    unowned
    unowned
    unowned
        Waiting to be notified:
            Class lock: Java stack lock: Code rewrite lock: Heap lock: Has finalization queue lock: Monitor IO lock: Child death monitor: Event monitor: I/O monitor: Alarm monitor: "clock handler"
    unowned
    unowned
    monitor owner: "thread applet-QuickTest"
Thread Alarm Q:
    sys_thread_t 0xef4c0de0 [Timeout in 757 ms]
    Sbrk lock: Monitor cache lock: Monitor registry: Abort (core dumped)