In that case, I would recommend my initial solution even more. XHTML is the "proper" way to do it. XHTML is the new (re)formulation of HTML in XML and is the markup language of today and the future. It's often necessary to use the XHTML declaration to tell browsers you're feeding them proper and well formed XHTML, and they should act accordingly.
Using old doc type declarations just to make a link work is not acceptable for me, as it would also mean other issues with the page (for example, a whole different box-model interpretation in Internet Explorer). It feels like a nasty work around, while there are better, cleaner and less problematic alternatives....