On Win32 XP machine.

Install June 5th 2006 master nightly build, running swingset2 demo:

java -jar SwingSet2.jar

Under "Look & Feel" menu, switch to windows look and feel, you will get exception:

(mustang b86 promoted build is okay)

Failed loading L&F: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
java.lang.ClassCastException: javax.swing.KeyStroke cannot be cast to java.lang.
Comparable
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing
.plaf.ColorUIResource cannot be cast to java.util.List
        at javax.swing.plaf.metal.MetalUtils.drawGradient(Unknown Source)
        at javax.swing.plaf.metal.MetalInternalFrameTitlePane.paintComponent(Unk
nown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JLayeredPane.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JLayeredPane.paint(Unknown Source)
        at javax.swing.JComponent.paintChildren(Unknown Source)
        at javax.swing.JComponent.paint(Unknown Source)
        at javax.swing.JComponent.paintToOffscreen(Unknown Source)
        at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
        at javax.swing.RepaintManager.paint(Unknown Source)
        at javax.swing.JComponent._paintImmediately(Unknown Source)
        at javax.swing.JComponent.paintImmediately(Unknown Source)
        at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
        at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
        at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
        at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknow
n Source)
        at java.awt.event.InvocationEvent.dispatch(Unknown Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing
.KeyStroke cannot be cast to java.lang.Comparable
        at java.util.TreeMap.compare(Unknown Source)
        at java.util.TreeMap.put(Unknown Source)
        at java.util.TreeSet.add(Unknown Source)
        at com.sun.java.swing.plaf.windows.WindowsTabbedPaneUI.installDefaults(U
nknown Source)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.installUI(Unknown Source)
        at javax.swing.JComponent.setUI(Unknown Source)
        at javax.swing.JTabbedPane.setUI(Unknown Source)
        at javax.swing.JTabbedPane.updateUI(Unknown Source)
        at javax.swing.SwingUtilities.updateComponentTreeUI0(Unknown Source)
        at javax.swing.SwingUtilities.updateComponentTreeUI0(Unknown Source)
        at javax.swing.SwingUtilities.updateComponentTreeUI(Unknown Source)
        at SwingSet2$6.run(SwingSet2.java:973)
        at java.awt.event.InvocationEvent.dispatch(Unknown Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)


You cannot start java control panel also, because of the same problem:

Exception in thread "main" java.lang.ClassCastException: javax.swing.KeyStroke c
annot be cast to java.lang.Comparable
        at java.util.TreeMap.compare(Unknown Source)
        at java.util.TreeMap.put(Unknown Source)
        at java.util.TreeSet.add(Unknown Source)
        at com.sun.java.swing.plaf.windows.WindowsTabbedPaneUI.installDefaults(U
nknown Source)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.installUI(Unknown Source)
        at javax.swing.JComponent.setUI(Unknown Source)
        at javax.swing.JTabbedPane.setUI(Unknown Source)
        at javax.swing.JTabbedPane.updateUI(Unknown Source)
        at javax.swing.JTabbedPane.<init>(Unknown Source)
        at javax.swing.JTabbedPane.<init>(Unknown Source)
        at com.sun.deploy.panel.ControlPanel.initComponents(Unknown Source)
        at com.sun.deploy.panel.ControlPanel.<init>(Unknown Source)
        at com.sun.deploy.panel.ControlPanel.main(Unknown Source)