🚀 go-pugleaf

I have an application developed under JBuilder 2 with Swing 1.0.3 and
now running on JRE 1.1.6.  This works.  I replaced swingall.jar and
windows.jar with Swing 1.1beta2 files on the system running the JRE.  I
did not install 1.1beta2 on the JBuilder system nor did I recompile. 
Now, when I try to run the application under the JRE I get an exception
apparently related to the TreeControl class.

Does anyone know what might be happening?  Do I have to recompile with
the Swing 1.1beta2 files?  If so, why?  Are applications that use Swing
upward compatible?

Thanks for any suggestions!

Guy

[Loaded com/sun/java/swing/JRootPane$1.class from .\swingall.jar]
[Loaded com/sun/java/swing/JInternalFrame.class from .\swingall.jar]
[Loaded com/sun/java/swing/JRootPane$RootLayout.class from
.\swingall.jar]
[Loaded borland/jbcl/control/TextControl.class from
.\jbcl2.0-rt.jar][Loaded
borland/jbcl/dataset/DataSetException.java.lang.NullPointerException
        at
borland.jbcl.view.TreeView.addFocusListener(TreeView.java:420)
        at com.sun.java.swing.JComponent.enableSerialization(Compiled
Code)
        at com.sun.java.swing.JComponent.<init>(Compiled Code)
        at com.sun.java.swing.JScrollPane.<init>(JScrollPane.java:200)
        at com.sun.java.swing.JScrollPane.<init>(JScrollPane.java:248)
        at borland.jbcl.view.TreeView.<init>(TreeView.java:41)
        at borland.jbcl.control.TreeControl.<init>(TreeControl.java:37)
        at np.NetworkEditor.<init>(NetworkEditor.java:51)
        at np.NPDemo.<init>(NPDemo.java:18)
        at np.NPDemo.main(NPDemo.java:46)