Fixed div with scroll -> deactivate circle expansion effect

Hello,

I’ve added a jquery effect to have a div (containing the list of categories) kept “fixed” while scrolling the page. I’ve found a nice script on the web, which I share here in case someone is interested :

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.js"></script>
<script>
						$(function () {
var msie6 = $.browser == 'msie' && $.browser.version < 7;						  if (!msie6) {
						    var top = $('#categ').offset().top - parseFloat($('#categ').css('margin-top').replace(/auto/, 0));
						    $(window).scroll(function (event) {
						      // what the y position of the scroll is
						      var y = $(this).scrollTop();

						      // whether that's below the form
						      if (y >= top) {
						        // if so, ad the fixed class
						        $('#categ').addClass('fixed');
						      } else {
						        // otherwise remove it
						        $('#categ').removeClass('fixed');
						      }
						    });
						  }
						});
						</script>

Now, this script works very well, but it deactivates the effect on the circled images… Is there a way to have both effects? Or one cancels the other?