In playing with a Swing app on 1.5 b35 I got the following exception:
sun.java2d.InvalidPipeException: bounds changed
        at sun.awt.X11Renderer.devCopyArea(Native Method)
        at sun.awt.X11SurfaceData.copyArea(X11SurfaceData.java:388)
        at sun.java2d.SunGraphics2D.copyArea(SunGraphics2D.java:1862)
        at javax.swing.JViewport.blitWindowGraphics(JViewport.java:1673)
        at javax.swing.JViewport.blitDoubleBuffered(JViewport.java:1591)
        at javax.swing.JViewport.windowBlitPaint(JViewport.java:1553)
        at javax.swing.JViewport.setViewPosition(JViewport.java:1083)
        at
+javax.swing.plaf.basic.BasicScrollPaneUI.syncScrollPaneWithViewport(BasicScroll+PaneUI.java:322)
        at
+javax.swing.plaf.basic.BasicScrollPaneUI$Handler.viewportStateChanged(BasicScro+llPaneUI.java:855)
        at
+javax.swing.plaf.basic.BasicScrollPaneUI$Handler.stateChanged(BasicScrollPaneUI+.java:797)
        at javax.swing.JViewport.fireStateChanged(JViewport.java:1342)
        at
+javax.swing.JViewport$ViewListener.componentResized(JViewport.java:1260)
        at java.awt.Component.processComponentEvent(Component.java:5291)
        at java.awt.Component.processEvent(Component.java:5245)
        at java.awt.Container.processEvent(Container.java:1961)
        at java.awt.Component.dispatchEventImpl(Component.java:3933)
        at java.awt.Container.dispatchEventImpl(Container.java:2019)
        at java.awt.Component.dispatchEvent(Component.java:3781)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
        at
+java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:+234)
        at
+java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:16+3)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149) at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
                                                                                
This happened when the window was being resized and scrolling resulted.
I tried to get a consistant test case but I couldn't.