Help. Membership links redirect

HI,

I am setting up membership on this site.

It was working wonderfully, but now the membership links redirect to the home page but i havent changed anything

http://startup.smart-business-solutions.co.uk/memberships/ go through to any of these memberships and scroll to bottom to click sign up and it redirects to home page.

Even though if you right click and select copy link you can see that it is the membership link, but even then pasting that in to url redirects to homepage

Please help