Android 4.0: http://jarofgreen.co.uk/wp-content/uploads/2012/06/Screensho...

In fact, I see this so much here's a blog post about it: http://jarofgreen.co.uk/2012/06/fixed-page-elements-must-die...

I commented on your blog too, but I just want to let you know that I've pushed a quick fix for the mobile browsers, and I'm looking into making a proper mobile version now. Thanks for reporting this.

It's better now. I can see the menu when I scroll but only for a second before it clears.

(latest mobile Safari)