Problem with Spark datagrid in flash builder 4.7

[SWiSHZOOM]

hi

I'm creating a project in fb 4.7 and now i am facing weird problem with spark.datagrid in specific in the columns headerText when i type it in Arabic with two words like "تاريخ الجلسة" i get this error:

RangeError: Error #1125: The index 0 is out of range 0.
          at spark.components::Label/getNextTruncationPosition()
          at spark.components::Label/truncateText()
          at spark.components::Label/http://www.adobe.com/2006/flex/mx/internal::composeTextLines()
          at spark.components.supportClasses::TextBase/updateDisplayList()
          at mx.core::UIComponent/validateDisplayList()
          at mx.managers::LayoutManager/validateClient()
          at mx.core::UIComponent/validateNow()
          at spark.components.gridClasses::GridColumnHeaderGroupLayout/updateDisplayList()
          at spark.components.supportClasses::GroupBase/updateDisplayList()
          at spark.components::Group/updateDisplayList()
          at mx.core::UIComponent/validateDisplayList()
          at spark.components::Group/validateDisplayList()
          at mx.managers::LayoutManager/validateDisplayList()
          at mx.managers::LayoutManager/doPhasedInstantiation()
          at mx.managers::LayoutManager/doPhasedInstantiationCallback()

but when it's in english it's work perfect.

thanks.

[asaad970]

I have the same problem but in buttons placed in form item when i removed th form item tag and put all the buttons in vgroup no problem and labels are oky i am using flash builder 4.6