[xwiki-users] Clean URL Issues

I'm running XWiki 1.6.1 as a root application in Jetty. I've made all the modifications on http://platform.xwiki.org/xwiki/bin/view/Main/ShortURLs, but prototype.js is getting included as "/prototype.js", which returns a not found message. In the comments on the Short URLs article, someone mentions that they had the same issue, and had to add another servlet mapping. How do I do this? Jonathan