Java Version: 1.7.0-ea-b108 Swat build
Platform: Solaris-sparc SunOS vm-t2000-04a 5.10 Generic_141444-09 sun4v sparc SUNW,Sun-Fire-T200

Problem:
One of vm swat test SwingSet2 threw exceptions with -server -Xmixed option as below:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
  at javax.swing.plaf.basic.BasicScrollBarUI.layoutHScrollbar(BasicScrollBarUI.java:757)
  at javax.swing.plaf.basic.BasicScrollBarUI.layoutContainer(BasicScrollBarUI.java:866)
  at java.awt.Container.layout(Container.java:1490)
  at java.awt.Container.doLayout(Container.java:1479)
  at java.awt.Container.validateTree(Container.java:1663)
  at java.awt.Container.validateTree(Container.java:1672)
  at java.awt.Container.validate(Container.java:1598)
  at javax.swing.RepaintManager.validateInvalidComponents(RepaintManager.java:653)
  at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1620)
  at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:660)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:209)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:118)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

To Reproduce the problem:
Run SwingSet2 in solaris-sparc machine: vm-t2000-04a
/export/jdk/jdk1.7.0/bin/java -jar -d32 -server -Xmixed -cp /export/jdk/jdk1.7.0/demo/jfc/SwingSet2.jar

The log file is as attaached.
You can take a look at the below link too:
http://sqeweb.sfbay.sun.com/nfs/results/vm/gtee/JDK6UR/SWAT/VM/6-swat/2010-09-02/vm/solaris-sparc/server/mixed/solaris-sparc_server_mixed_vm.swat_01/analysis.html