Edward's last-child CSS psuedo-class

Does anyone use Edward’s IE8.js (http://code.google.com/p/ie7-js/), which allows IE to use advanced CSS psuedo classes? On his homepage (http://dean.edwards.name/IE7/), he promised that the last-child selector would work. So far, I’ve only been able to get first-child to work.

Top: IE8 and IE7
Bottom: FF3

<div id="nav">
   <a href="#">register</a>
   <a href="#">login</a>
   <a href="#">help</a>

#nav a {
   border-right: 1px solid #000;

#nav a:last-child {
   border-right: none;

What’s strange is that there was an issue filed (http://code.google.com/p/ie7-js/issues/detail?id=171&q=last-child) complaining about how last-child doesn’t work. And then someone responded and said to include IE8.js, not IE7.js. That’s what I did, but no dice…