Oh is it a mime type issue what mime type are you serving your stylesheet
with? If you serve it with text/plain or text/html or some other non xml
type mozilla won't play.

title must not be empty.
and there are more things missing in your stylesheet to make it XHTML, see my comments in my earlier post. But that shouldn't stop browsers from rendering your output, which is close enough to XHTML.

You are not using your xhtml namespace. Furthermore, the namespace is not the correct namespace. See my earlier post. You are creating HTML, ok, but not XHTML.

That was David's suggestion, not mine. I just re-emphasized ;)
I am wondering what you mean with "value-of's" or what you use to look at you core content. If you use PHP, and you use it from your browser, do you actually use View Source? I tried you example, and it rendered like a tree, the same that displays on David's site.

This is no use. Once you do this, the output fails to be HTML. HTML still does not have an element <test> and will never have.

In addition to checking the content-type of your output that David suggests, try running it locally like I did, rename the output xxx.html and serve the html page. If you now still see nothing, it really is some configuration error of your Apache or other server. If you suddenly see the correct output, it is also a configuration error: likely the content-type in the HTTP headers (but that shouldn't stop the View Source from showing the actual content).