Here is the code I used

<script type="text/javascript">
   $(document).ready(function(){
           $('h1').css({'border':'1px solid #ccc'});
           console.log($('h1').css('border'));
   });
</script>
<h1>Some Message</h1>

And the output using alert or using firebug is:

''(an empty string)''

In IE9 ''border-width'' is detected and not the whole border property.