Dixi Theme and Contact Form 7

Hi all,
I'm using Dixi as a CMS for school websites. I'm also using Contact Form 7 for contact and enrolment forms on these sites.

I've got a weird problem - the css menu is appearing behind the form. Here's an example: http://netns.ie/contact
Hover over the policies link and you'll see the problem.

Just wondering if anyone had this with Dixi before and what the fix is? Thanks in advance.

Fiona