Possible regression moving from build #452 to #455

this works in build 452, but not anymore in 455, i'm trying to change the color of clicked words to red.

am I doing anything wrong?

...

... // create text flow, with paragraph and spans in it

...

_textFlow = new TextFlow();

var p:ParagraphElement = new ParagraphElement();

span.tlf_internal::getEventMirror().addEventListener(MouseEvent.CLICK, tfmo); // to enable regions

var span:FlowElement;

span = new SpanElement();

(span as SpanElement).text = "hello"

span.format = ef;  // ef is some TextLayoutFormat I created earlier

span.setStyle("wordObject", currWord);

span.tlf_internal::getEventMirror().addEventListener(MouseEvent.CLICK, tfmc); // to enable regions

p.addChild(span);

_textFlow.addChild(p);

var cc:ContainerController = new ContainerController(container, container.width, container.height);

_textFlow.flowComposer.addController(cc);

_textFlow.addEventListener(CompositionCompletionEvent.COMPOSITION_COMPLETE, onCompositionComplete);

_textFlow.flowComposer.updateAllControllers();

...

...

...

private function tfmc(event:MouseEvent):void

{

// LOCATE THE REGION

var line:TextLine = event.currentTarget as TextLine;

var tfl:TextFlowLine  = line.userData;

var atomIdx:int = line.getAtomIndexAtPoint(event.stageX, event.stageY);

var rec:Rectangle = line.getAtomBounds(atomIdx);

var regions:Vector.<TextLineMirrorRegion> = line.mirrorRegions;

var theRegionIndex:int;

for (var i:int = 0; i < regions.length; i++)

{

     if (regions.bounds.intersects(rec))

     {

          theRegionIndex = i;

          break;

     }

}

var region:TextLineMirrorRegion = line.mirrorRegions[theRegionIndex];

trace(region.element.text);

// GOT THE REGION, CHANGE TEXT ELEMENT COLOR TO RED

var el:ContentElement = region.element;

var newEl:ElementFormat  = region.element.elementFormat.clone();

newEl.color = 0xff0000;

el.elementFormat = newEl;

_textFlow.flowComposer.updateAllControllers();

}