IE 8.0 shows jQueryUI Tabs with small defect

IE 8.0 shows jQueryUI Tabs with small defect

I've noticed a small defect of jQueryUI Tabs in IE 8.0. If any tab except first is selected, there is no thin background colored line between inactive tabs and palette of active tab. If first tab is selected this line is displayed.
Here is a simple code I reproduce this small shortcoming with:
  1. <html>
  2.     <head>
  3.         <meta http-equiv="Content-Type" content="text/html; charset=windows-1251">
  4.         <!-- jQuery -->
  5.         <script type="text/javascript" src="jquery-1.4.2.js"></script>
  6.         <!-- jQueryUI -->
  7.         <script type="text/javascript" src="ui/js/jquery-ui-1.8.5.custom.min.js"></script>
  8.         <link href="ui/css/ui-lightness/jquery-ui-1.8.5.custom.css"  media="screen" rel="stylesheet" type="text/css">
  9.         <script type="text/javascript">
  10.             $(function(){
  11.                 $("#tabs").tabs();
  12.             });
  13.         </script>
  14.     </head>
  15.     <body>
  16.         <div id="tabs" style="width: 99%;">
  17.             <ul>
  18.                 <li><a href="#tabs-1">User settings</a></li>
  19.                 <li><a href="#tabs-2">Menu management</a></li>
  20.                 <li><a href="#tabs-3">"Help" section management</a></li>
  21.                 <li><a href="#tabs-4">Reason of registration</a></li>
  22.             </ul>
  23.             <div id="tabs-1">Some content</div>
  24.             <div id="tabs-2">Another content</div>
  25.             <div id="tabs-3">Here is something too</div>
  26.             <div id="tabs-4">BlaBlaBla</div>
  27.            </div>
  28.     </body>
  29. </html>
And here is screenshots illustrating this problem:




In Firefox 3.6 it looks ok. Here I haven't this problem too both in FF 3.6 and IE 8.0.