Width of Table cell based on colgroup not working

Setting width for table cell using colgroup not works in IE9

<table id="Grid1_Table" class="Table">
    <colgroup>
        <col style="width:20px">
        <col style="width:20px">
        <col style="width:180px">
        <col style="width:200px">
    </colgroup>
    <tbody>
        <tr>
            <td class="RowHeader"><div>&nbsp;</div></td>
            <td class="RecordPlusCollapse"><div>&nbsp;</div></td>
            <td colspan="2" class="GroupCaption">Order ID: 0 - 1 Items</td>
        </tr>
    </tbody>
</table>

.RowHeader
{
    background-color : black;
}
.GroupCaption
{ 
    background-color : #868981;
}
.RecordPlusCollapse
{
    background-color : red;
}
.Table{
    width: 100%;
}

First 2 <td> width is not as colgroup in IE9. Not sure why width differs.

http://jsfiddle.net/KgfsM/3/