             perfUtil.markTime("validateSize().start");
         }
 
+        if (FlexVersion.compatibilityVersion >= FlexVersion.VERSION_4_5)
+            validateEstimatedSizes(invalidateSizeQueue.clone());
+        
         var obj:ILayoutManagerClient = ILayoutManagerClient(invalidateSizeQueue.removeLargest());
         while (obj)
         {

    }

    /**
     *  Validates all components whose properties have changed and have called
     *  the <code>invalidateSize()</code> method.  
     *  It calls the <code>validateSize()</code> method on those components

                invalidatePropertiesFlag = false;
                invalidateClientPropertiesFlag = false;
            }

            if (FlexVersion.compatibilityVersion >= FlexVersion.VERSION_4_5)
                validateEstimatedSizes(invalidateSizeQueue.clone(target))
            // trace("--- LayoutManager: validateSize --->");

            obj = ILayoutManagerClient(invalidateSizeQueue.removeLargestChild(target));
