I am able to consistantly lock up NB 3.2.
Eventually, an out-of-memory exception is thrown.
(Presumably) since memory is exhausted, no stack trace is generated.
Once I could reproduce the hang, I was able to signal the
JVM to dump the thread stack. Such a dump is the origin of the 
following trace.

I am running in MDI mode with the Windows L&F.
Double clicking the Maximize button of the source viewer does this to the stack:

    "AWT-EventQueue-0" prio=7 tid=0x9c3450 nid=0x2a8 runnable [0x9993000..0x99bfdc4]
        at
sun.awt.windows.WGlobalCursorManager.findHeavyweightUnderCursor(Native Method)
        at sun.awt.GlobalCursorManager._updateCursor(GlobalCursorManager.java:182)
        at
sun.awt.GlobalCursorManager.updateCursorImmediately(GlobalCursorManager.java:91)
        at java.awt.Container.addImpl(Container.java:396)
        at javax.swing.JLayeredPane.addImpl(JLayeredPane.java:201)
        at java.awt.Container.add(Container.java:284)
        at javax.swing.JLayeredPane.setLayer(JLayeredPane.java:343)
        at javax.swing.JLayeredPane.setPosition(JLayeredPane.java:424)
        at javax.swing.JLayeredPane.moveToFront(JLayeredPane.java:395)
        at javax.swing.JInternalFrame.moveToFront(JInternalFrame.java:1024)
        at
javax.swing.DefaultDesktopManager.activateFrame(DefaultDesktopManager.java:207)
        at
com.sun.java.swing.plaf.windows.WindowsDesktopManager.activateFrame(WindowsDesktopManager.java:65)
        at
javax.swing.plaf.basic.BasicInternalFrameUI.activateFrame(BasicInternalFrameUI.java:624)
        at
javax.swing.plaf.basic.BasicInternalFrameUI$InternalFramePropertyChangeListener.propertyChange(BasicInternalFrameUI.java:433)
        at
javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:153)
        at javax.swing.JComponent.firePropertyChange(JComponent.java:3721)
        at javax.swing.JInternalFrame.setSelected(JInternalFrame.java:966)
        at
javax.swing.DefaultDesktopManager.minimizeFrame(DefaultDesktopManager.java:103)
        at
javax.swing.plaf.basic.BasicInternalFrameUI.minimizeFrame(BasicInternalFrameUI.java:606)
        at
javax.swing.plaf.basic.BasicInternalFrameUI$InternalFramePropertyChangeListener.propertyChange(BasicInternalFrameUI.java:420)
        at
javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:153)
        at javax.swing.JComponent.firePropertyChange(JComponent.java:3721)
        at javax.swing.JInternalFrame.setMaximum(JInternalFrame.java:890)
   
This sequence of calls is repeated until the stack gives out:

        at
org.netbeans.core.windows.frames.InternalFrameTypeImpl.setMaximum(InternalFrameTypeImpl.java:198)
        at
com.sun.java.swing.plaf.windows.WindowsDesktopManager.activateFrame(WindowsDesktopManager.java:76)
        at
javax.swing.plaf.basic.BasicInternalFrameUI.activateFrame(BasicInternalFrameUI.java:624)
        at
javax.swing.plaf.basic.BasicInternalFrameUI$InternalFramePropertyChangeListener.propertyChange(BasicInternalFrameUI.java:433)
        at
javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:153)
        at javax.swing.JComponent.firePropertyChange(JComponent.java:3721)
        at javax.swing.JInternalFrame.setSelected(JInternalFrame.java:966)
        at
javax.swing.DefaultDesktopManager.maximizeFrame(DefaultDesktopManager.java:91)
        at
javax.swing.plaf.basic.BasicInternalFrameUI.maximizeFrame(BasicInternalFrameUI.java:600)
        at
javax.swing.plaf.basic.BasicInternalFrameUI$InternalFramePropertyChangeListener.propertyChange(BasicInternalFrameUI.java:416)
        at
javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:153)
        at javax.swing.JComponent.firePropertyChange(JComponent.java:3721)
        at javax.swing.JInternalFrame.setMaximum(JInternalFrame.java:890)