Scrolling changes with build 455 (706481)

It seems something changed with scrolling from build 452 (705274) to build 455 (706481).  The below works fine in 452 (705274) but in 455 (706481) if i scroll down to the bottom i cant scroll back to the top.  I origanlly thought it was an issue with images b/c we have a lot of InlineGraphicElements and saw some comments about scrolling issues with images in the last change log but made this test and its happening without them.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
     xmlns:mx="http://www.adobe.com/2006/mxml"
     layout="absolute"
     horizontalAlign="center"
     applicationComplete="init()">

    <mx:Script>
         <![CDATA[
             import flashx.textLayout.BuildInfo;
             import flash.utils.*;
             import flash.text.engine.*;
             import flash.display.*;
             import flash.events.*;
            
             import flashx.textLayout.elements.*;
             import flashx.textLayout.formats.*;
             import flashx.textLayout.container.*;
             import flashx.textLayout.events.*;
             import flashx.textLayout.edit.*;
    
             private var container:Sprite = null;

            public function init() : void
             {
                 container = new Sprite;
                    textArea.rawChildren.addChild(container);
                    
                  var textFlow:TextFlow = new TextFlow;
                  textFlow.interactionManager = new EditManager;
                  textFlow.flowComposer.addController(new ContainerController(container, textArea.width, textArea.height));
    
                 var i : uint = 10;
                 var total : uint = i;
                 while( i )
                 {
                     var dv : DivElement = new DivElement;
                     var sp : SpanElement = new SpanElement;
                     sp.text = i + "/" + total + " " + BuildInfo.kBuildNumber;
                     var p : ParagraphElement = new ParagraphElement;
                    
                     p.addChild(sp);
                     dv.addChild(p)
                     textFlow.addChild( dv );
                    
                     i--;
                 }
                
                   textFlow.interactionManager.setSelection(0,0);
                 textFlow.interactionManager.setFocus();
                 textFlow.flowComposer.updateAllControllers();
             }
    
         ]]>
     </mx:Script>

    <mx:Canvas
         height="50"
         width="100"
         backgroundColor="#FFFFFF"
         id="textArea">   
     </mx:Canvas>

</mx:Application>