Problem with jQuery Round in IE 6&7

Problem with jQuery Round in IE 6&7


Hi,
I used this code in my page to gain rounded corner :
<script type="text/javascript">
$(document).ready(function(){
$("div#right_column").each(function(){
        $(this).corner("round");
    });
});
</script>
There is no problem in FF but I have problem with IE , please have a
view here :
http://i33.tinypic.com/2re6u6u.png
I don`t have online sample now :(
What can I do ?