         if (viewport)
         {
             var vpPageSize:Number = Math.abs(viewport.getVerticalScrollPositionDelta(
-                (newValue > value) ? ScrollUnit.PAGE_DOWN : ScrollUnit.PAGE_UP));
+                (newValue > value) ? NavigationUnit.PAGE_DOWN : NavigationUnit.PAGE_UP));
             super.animatePaging(newValue, vpPageSize);
             return;
         }        


import spark.components.supportClasses.ScrollBar;
import spark.core.IViewport;
import spark.core.ScrollUnit;

//--------------------------------------
//  Other metadata

            // implementation.
            oldPageSize = pageSize;
            pageSize = Math.abs(viewport.getVerticalScrollPositionDelta(
                (increase) ? NavigationUnit.PAGE_DOWN : NavigationUnit.PAGE_UP));
        }
        super.page(increase);
        if (viewport)
