I have several XamTextEditor/XamComboEditor controls in a TabItemEx.  Their values are binded to an object, like this: SelectedItem="{Binding Path=Status, UpdateSourceTrigger=LostFocus, ValidatesOnDataErrors=True}"

The object implements IDataErrorInfo.  When the property has an error the control is surrounded by a thin red border.  When I activate another tab and then go back to the tab with control with the error the border is gone.  Even though object still has an error.

Any ideas?