@TIm,
no sweat. Once things go live I am happy to test the compatibility with my box of tools.
Here's another, the W3G HTML checker: http://www.htmlhelp.com/tools/validator/
At the risk of sounding really old, what's the zip file for, do I have to test it locally? Why not just fire it up? That way we can all see it.
This thread is getting really long, is it time for a new thread called "Live playground design, comments please?"
D