Add to cart button does not work when option is required

All the add to cart buttons will not work if there is the product option is set to "required" in the admin panel.

When I click the button, the page just refresh but nothing is added to shopping cart.

The url is www.ajtacitacl.co.nz

vqmod, outofstock and disableaffiliatev2.2 extension are installed.

can you verify if you entered the store url corectly cause I cant access it to have a look.