When I reduce this website to the point where the responsive menu appears, clicking the handle results only in a little bit of extra space in the header. Additionally, this space doesn't toggle when you click the handle a second time.
1. There doesn't appear to be any javascript errors
2. Judging by the source code the select element is present, simply not showing.
I'm sorry - I think I may have mislead you slightly. I gave you a link to the site via it's virtual account name, not it's fully qualified domain name. The reason for this is that I have previously discussed a client's website on a forum and ended up with the forum appearing higher in search results than their actual website!
The link you want it actually
man-tam-ari-time.com/joomla2013/
(please remove all hyphens - sorry for being paranoid). If you use this address you will find that the javascript errors aren't there.
I have followed your advice regarding jQuery...
- removed inclusion of my jquery files
- disabled "jQuery Easy" (3rd party extension)
- disabled breadcrumbs (native)
- disabled smart search (native)
I was slightly surprised to learn that breadcrumbs and smart search use jQuery instead of MooTools!
So I have managed to remove all reference to and requirement of jQuery and yet I still have the same issue - when reducing the site to single column (on desktop and iPhone) the responsive menu handle appears but only results in a small increase in height of the header when clicked. I notice in the DOM however that the menu is there - it just isn't being revealed.
I have noticed, however, that if I choose "panel" there is no visible evidence of the responsive menu at all, but if I choose "selectbox" the menu appears without clicking the handle but it is slightly fractured but appears to be a panel, not a select box.
At this time I have re-enabled the jQuery because my client will be viewing the site today, however I am convinced it's not a jQuery/MooTools conflict in this situation.
My Mobile / Responsive Menu was doing the EXACT same thing.
I was a little upset that the original poster didn't come back to this thread and post what his findings were.
I will post mine though.