Well, firstly, it's very possible that it's working. The two default - *.xsl stylesheets were made to duplicate the current functionality of the html. They were made as a baseline, so people could see the xslt that designs the current layout, and hopefully would be able to change things easily themselves.

Now, if you still think you're having a problem (or if anyone else is)...

Which browser do you have, and which stylesheet did you rename to default.xsl

If you have IE 5 or 5.5 and have not upgraded your XML parser to 3.0 in "replace" mode, use the "Working Draft" stylesheet. I think it was named default - WD.xsl

If you are using Mozilla, IE 6, or IE 5 / 5.5 with MSXML 3.0 in "replace" mode, use either the default - 1.0.xsl or default - alt colours - 1.0.xsl stylesheet.

Andy had some links for upgrading your xml parser here. You can also find some good info at netcrucible for msxml questions.