Flex中让鼠标移至AdvancedDataGrid的行上不自动修改显示效果

package com.nauproject.apm.common.custom
{
    import flash.events.MouseEvent;

    import mx.controls.AdvancedDataGrid;
    import mx.core.mx_internal;
    use namespace mx_internal;

    public class ApmAdvancedDataGrid extends AdvancedDataGrid
    {
        public function ApmAdvancedDataGrid()
        {
            super();
        }

        override protected function mouseOverHandler(event:MouseEvent):void {
        }

        override protected function mouseDownHandler(event:MouseEvent):void {
        }
    }
}

package com.nauproject.apm.common.custom
{
    import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;

    [DefaultProperty("apmColumn")]

    public class ApmAdvancedDataGridColumn extends AdvancedDataGridColumn
    {
        public function ApmAdvancedDataGridColumn(columnName:String=null)
        {
            super(columnName);
        }

    }
}

<custom:ApmAdvancedDataGrid id="reqResearchSeeds" headerHeight="0"
                        sortableColumns="false"
                        selectionMode="multipleCells"
                        alternatingItemColors="[0xccffcc, 0xfafad2]"
                        variableRowHeight="true"
                        designViewDataType="flat"
                        borderStyle="none"
                        verticalGridLineColor="#FFFFFF"
                        themeColor="#FFFFFF"
                        width="100%"
                        height="100%">
                        <custom:columns>
                            <custom:ApmAdvancedDataGridColumn headerText="Album" dataField="album" width="50"/>
                            <custom:ApmAdvancedDataGridColumn itemRenderer="com.nauproject.apm.common.custom.LabelTextReqRes"/>
                        </custom:columns>
                    </custom:ApmAdvancedDataGrid>

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml">
    <mx:Script>
        <!--[CDATA[
            import mx.collections.ArrayCollection;
            import mx.controls.AdvancedDataGrid;
        ]]-->
    </mx:Script>
    <mx:VBox>
        <mx:Label id="lab1" text="◆研究テ?`マ"/>
         <mx:Text id="txt1" htmlText="{data.rthema}" width="455" y="{lab1.height}"/>    
         <mx:Label id="lab2" text="◆キ?`ワ?`ド" y="{lab1.height + txt1.height}"/>
         <mx:Text id="txt2" htmlText="{data.keyword}" width="455" y="{lab1.height + txt1.height + lab2.height}"/>
         <mx:Label id="lab3" text="◆研究の特??" y="{lab1.height + txt1.height + lab2.height + txt2.height}"/>
         <mx:Text id="txt3" htmlText="{data.rtoku}" width="455" y="{lab1.height + txt1.height + lab2.height + txt2.height + lab3.height}"/>
         <mx:Label id="lab4" text="◆技?g移?の可能性" y="{lab1.height + txt1.height + lab2.height + txt2.height + lab3.height + txt3.height}"/>
         <mx:Text id="txt4" htmlText="{data.rkanousei}" width="455" y="{lab1.height + txt1.height + lab2.height + txt2.height + lab3.height + txt3.height + lab4.height}"/>
    </mx:VBox>
</mx:Canvas>