null pointer exception when clicking on JCheckbox

[sonali majumdar]

Hi all,
I have overridden the JTable Header of my JTable to show a JCheckbox. I get this error each time I select/deselect. This error is only on JRE1.6. It does not occur on JRE1.5.
Let me know if anybody has faced a similar problem and what is the solution ?

 Exception in thread "AWT-EventQueue-2" java.lang.NullPointerException
	at javax.swing.plaf.basic.BasicTableHeaderUI$MouseInputHandler.mouseClicked(Unknown Source)
	at java.awt.AWTEventMulticaster.mouseClicked(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(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)   

[Michael Dunn]

checkbox in header works OK for me, using java 1.6.0_20/vista

[Rob Spoor]

How about showing an SSCCE?