Paul,
You'll need also to add an entry into the \App_GlobalResources\SiteMap.resx resource file. double click on it and add the Name Test and a value that relates to the link that you're trying to. once you look at the resx file, you'll get an idea of how it relates to exisiting entries in the web.sitemap file.
a bit fiddly to figure out, but more to allow for multi language stuff really.
jimi
http://www.originaltalent.com