[html5] HTML5 validator behavior issue

[Jacob Kristensen]

>It's invalid, and it would be ideal if the validator said it was invalid,
>but for various reasons it's essentially impossible for the validator to
>detect this particular mistake.

Just a small question, why is it considered invalid? It seems perfectly 
reasonable to use the display property to hide content, (espicially when 
working with CSS based menus).
Not that I've done it my self yet, since i prefer to keep my navigation 
visible at all times. Using dropdowns is usually totally overkill for a 
website, at least the ones that I've seen using dropdowns, and the ones I've 
worked with my self.

In any case, what would you suggest web designers to use instead?

Jacob Kristensen (Aka BlueBoden)
http://blueboden.com/