svn 19816 caused TileLayout virtualization failures in some cases

Steps to reproduce:
1. Compile and run this application:

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark">

<fx:Script>
<![CDATA[
import mx.collections.*;

public function createVariableItems(nItems:int):ArrayList {
var tempArray:Array = new Array(nItems);
for (var i:int = 0; i < nItems; i++)
tempArray[i] = (

{myItemIndex: i, minorSize: 100, majorSize: (20 + ((20 * i) % 100))}

);

return new ArrayList(tempArray);
}
]]
>
</fx:Script>

<s:Group id="containingGroup">
<s:Rect id="bgRect" top="0" left="0" right="0" bottom="0">
<s:fill>
<s:SolidColor color="0xe3e3e3" />
</s:fill>
</s:Rect>

<s:DataGroup width="500" height="500" clipAndEnableScrolling="true"
dataProvider="

{createVariableItems(500)}

">
<s:layout>
<s:TileLayout useVirtualLayout="true" orientation="rows" />
</s:layout>
<s:itemRenderer>
<fx:Component>
<s:ItemRenderer autoDrawBackground="false"
top="0" right="0" left="0" bottom="0">
<fx:Script>
<![CDATA[
override public function set data(value:Object):void

{ super.data = value; if(value == null) return; lbl.text = data.myItemIndex; forefrontRect.width = value.majorSize; forefrontRect.height = value.minorSize; }

]]
>
</fx:Script>

<s:states>
<s:State name="normal"/>
<s:State name="hovered"/>
<s:State name="selected"/>
</s:states>

<s:Rect id="bgRect" top="0" left="0" right="0" bottom="0">
<s:fill>
<s:SolidColor color="0xCCCCCC" />
</s:fill>
</s:Rect>

<s:Rect id="forefrontRect">
<s:fill>
<s:SolidColor color="0xA8C6EE"
color.hovered="0xCEDBEF"
color.selected="0xCCCCCC" />
</s:fill>
</s:Rect>

<s:Label id="lbl" top="1" left="1" />
</s:ItemRenderer>
</fx:Component>
</s:itemRenderer>
</s:DataGroup>

</s:Group>

</s:Application>

2.
3.

Actual Results:

All the renderers look the same except the gap in the first one. Hovering over the renderers is weird too, some seem to stick out under others.

Expected Results:

See the baseline and bad png attached that show how this used to look

Workaround (if any):