- 
    Type:
Bug
 - 
    Resolution: Cannot Reproduce
 - 
    Priority:
Critical
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    Affects Version/s: None
 - 
    Component/s: None
 - 
    None
 - 
    Environment:
eclipse3.6+tomcat5.5
 
when click the "+" to expand 2nd level on 28 rows or after, NullPointerException hanpped.
We use your demo and just add more data.
org.zkoss.zk.ui.impl.UiEngineImpl handleError:1256
严重: >>java.lang.NullPointerException
严重: >>java.lang.NullPointerException	
>>	at org.zkoss.pivot.impl.TabularPivotModel.getRawValues(TabularPivotModel.java:396)
>>	at org.zkoss.pivot.impl.TabularPivotModel.getRawValues(TabularPivotModel.java:334)
>>	at org.zkoss.pivot.demo.PivotDemoController.onPivotPopup$pivot(PivotDemoController.java:68)