Hi,
Yes, there's problem on your site. Our demo is based on Joomla 2.5. However, when I test it on my computer, the template's menu works the same for me with Joomla 3.1.
Maybe there are errors in version that's in download repository, so I have re-uploaded new version. Please re-download Wedding for Joomla 3.1 now from our site and re-install it.
Thanks
Milos