Sortable on ul - dragging an item does not make list scroll in IE9

Sortable on ul - dragging an item does not make list scroll in IE9

I am seeing an issue with Sortable in IE9 that list does not scroll as an item is being dragged down. Is it a bug or am I missing something here?

Here is the sample that I am working with -

  1. <style type="text/css">
     .sortable
        {
            border: 1px solid black;
            height: 200px;
            width: 368px;
            list-style-type: none;
            margin: 0px  ;
            overflow-y:scroll;
            padding:0px 0px 0px 0px;
            font-family: Verdana;
           
        }
       
    </style>
    <body>
     
    <ul id="sortable" class="sortable">
        <li>Item 1</li>
        <li>Item 2</li>
        <li>Item 3</li>
        <li>Item 4</li>
        <li>Item 5</li>
        <li>Item 6</li>
        <li>Item 7</li>
        <li>Item 8</li>
        <li>Item 9</li>
        <li>Item 10</li>
        <li>Item 11</li>
        <li>Item 12</li>
        <li>Item 12</li>
        <li>Item 13</li>
        <li>Item 14</li>
        <li>Item 15</li>
        <li>Item 16</li>
    </ul>
     
    <script>    $("#sortable").sortable();</script>