CSS Media Query Shortcoming in Firefox 3.6

Resize the window. According to the viewport size, the specific style kicks in. Neat! It means you can switch the layout according to the available space!

But: strange enough, Firefox does not "update" the Style if you resize the window below 515px (if it would, the "yellow" style would be used). Chrome does.

(Tested on Nov. 20,2010 in Firefox 3.6 and Google Chrome 7.0)