[Plugin: Responsive Slider]

I’ve installed the plugin on one site and it works perfectly, however on a second it doesn’t show up. I’ve put it in the template and if I view the source, I can see it’s there, but the li elements don’t seem to be styled like the working site does. You can see (or can’t see, rather) the non-working version here: http://www.thepunteroxford.co.uk/our-menus/

On the working site I see:
<li style="width: 100%; float: left; margin-right: -100%; display: none;">

on the non-working one, I see only:
<li>

Why might that be?