Fotiman - 1:33 am on Feb 26, 2011 (gmt 0)

Property text-shadow doesn't exist in CSS level 2.1

text-shadow was introduced in CSS3. So if you try to validate it as CSS 2.1, then you will get this error.

And what about the HTML validator?

You haven't specified any padding on the li, so the browser default will be used. You may want to specify the padding to ensure it's consistent cross-browser.