The Responsive behaviour is part of the Theme, based on Twitter Bootstrap framework.
Having looked at your site in Windows/Firefox and shrinking the page, I seem to lose the ‘3-bar menu’ completely which suggests that you’ve adjusted the CSS a little too far.
How are you adjusting your CSS, using CustomCSS panel or a Child Theme?
I’m using a css file based on whats in the blue.css file. (Yes i copied the blue.css and edited it) I know about the pros/cons using child themes but thats not the way i’ve done it.
edit: oh i see what you meant, its now back again
found the solution myself 🙂
for some reason the .navbar .nav element was set to absolute which caused the menu to be displayed outside the view.
Anyway Thank You 🙂