BlendMode の日本語入力で左上表示問題

/**
 * Copyright matsu ( http://wonderfl.net/user/matsu )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/psSU
 */

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init();">
	<mx:Script>
		<![CDATA[
		private function init():void
		{
			blendModeCheckBox.selected = true;
			blendModeCheckBoxCheck();
		}
		private function blendModeCheckBoxCheck():void
		{
			switch ( blendModeCheckBox.selected ) {
				case true:
					blendModeBox.blendMode = BlendMode.LAYER;
				break;
				case false:
					blendModeBox.blendMode = BlendMode.NORMAL;
				break;
			}
		}
		]]>
	</mx:Script>
	<mx:Box id="blendModeBox" width="100%" height="100%" backgroundColor="#cccccc" horizontalAlign="center" verticalAlign="middle">
		<mx:VBox>
			<mx:Label text="BlendMode を設定すると Text への日本語入力時に画面左上に表示される。"/>
			<mx:CheckBox id="blendModeCheckBox" label="BlendMode" click="blendModeCheckBoxCheck();"/>
			<mx:TextInput id="blendModeTextInput" width="200"/>
		</mx:VBox>
	</mx:Box>
</mx:Application>