pseudo-class support in IE (Internet Explorer)

I just realised (from reading online) that IE (sadly both 6 and 7) do not support either CSS pseudo-classes not JQuery last-child method (http://www.evotech.net/blog/2007/05/ie7-css-selectors-how-they-fail/) in strict XHTML mode. Strangely though IE7 supports first-child as long as there is a space before :first-child i.e:

li :first-child

JQuery If you apply this definition in Jquery, you will notice that IE browsers will not have the extra class added to your HTML

$(document).ready(function() {
//find the last main menu and secondary menu items and add a class to remove the right border in IE
$("#container #header #top_tools ul li:last-child").addClass ("last_menu");
$('#container #footer #popular ul li:last-child').addClass('last_menu');
});