User Registration page not opening after address update problem

[Phillipbarron242]

I have a problem with PrestaShop 1.4.4.1,

 

Customers were not able to add or update addresses which was mentioned in another post as possibly being due to using Smarty version 2. I followed the steps here (http://www.prestashop.com/forums/topic/98456-cant-update-or-add-new-address-as-customer/) to see if this would resolve the issue. It did not and introduced a new more fundamental error;

 

When users click Sign in - Sign up and try to create a new account, after entering an email address and clicking submit, the registration page no longer loads. There screen refreshes and responds "already registered" as pictured.

 

I am new to Prestashop and would greatly appreciate some guidance as to what might be the cause. I have not found any similar issues in the forum.

 

Many thanks