In ToolTipManager.java when a WindowPopup is created, the constraints are not set, so MS JVM has a problem. I have the fix. ( I also need to fix the use of WindowPopup vs PanelPopup, so this problem happens on Applications, and certain cases when Applets use JFrames/JDialogs).

If I call setToolTipText for any JComponent objet, then I get below
exception when Swing tries to display ToolTip. The ToolTip looks like
gray rectangle, without text.
BorderLayout: cannot add to layout: unknown constraint: null
java.lang.IllegalArgumentException: null source
        at java/util/EventObject.<init> (EventObject.java)
        at java/awt/AWTEvent.<init> (AWTEvent.java)
        at java/awt/event/ComponentEvent.<init> (ComponentEvent.java)
        at com/ms/awt/WHeavyPeer._internal_handleMoved
(WHeavyPeer.java)
        at com/ms/awt/peer/IToolkit.callbackEventLoop (IToolkit.java)
        at com/ms/awt/WToolkit.run (WToolkit.java)
        at java/lang/Thread.run (Thread.java)