Hi,
My guess is that you either have two templates that have html tags or that you are loading one template with an html tag twice and then putting one inside the other. Nevow won't stop you from doing this, even though in most cases, the result isn't very sensible.
Yes you are right. I found the problem was in the code that someone else wrote and committed to CVS. They had put something in the authentication system that was also including HTML.
Further to this, I have still seem to have a problem with the XHTML generated. When I load the page through firefox it does not render my inline SVG. However, when I save the page as something .xml and load the same page into firefox it does render the SVG. Is this something to do with the Content-Type not being set to application/xhtml+ xml ? If so, how can I set it? AW