try changing the crypt element code to:
<input type="hidden" name="Crypt" id="Crypt" value="<?php echo WA_Protx_VSPFormHash($WeeRideUK, "8GejG5SG2jCjMsbY", "".WAEC_getTimestamp() ."", "".$WeeRideUK->GrandTotal() ."", "GBP", "".WAEC_getTimestamp() ."", "http://www.weerideuk.co.uk/checkout_success.php", "http://www.weerideuk.co.uk/checkout_failure.php", "".((isset($_POST["email"]))?$_POST["email"]:"") ."", "sales@weerideuk.co.uk", "".((isset($_POST["shipping_lastname"]))?$_POST["shipping_lastname"]:"") ."", "".((isset($_POST["shipping_firstname"]))?$_POST["shipping_firstname"]:"") ."", "".((isset($_POST["shipping_street1"]))?$_POST["shipping_street1"]:"") ."", "".((isset($_POST["shipping_street2"]))?$_POST["shipping_street2"]:""). "", "".((isset($_POST["shipping_postcode"]))?$_POST["shipping_postcode"]:"") ."", "".((isset($_POST["shipping_city"]))?$_POST["shipping_city"]:"") ."", "".((isset($_POST["shipping_country"]))?$_POST["shipping_country"]:"") ."", "".((isset($_POST["lastname"]))?$_POST["lastname"]:"") ."", "".((isset($_POST["firstname"]))?$_POST["firstname"]:"") ."", "".((isset($_POST["street1"]))?$_POST["street1"]:"") ."", "".((isset($_POST["street2"]))?$_POST["street2"]:"") ."", "".((isset($_POST["postcode"]))?$_POST["postcode"]:"") ."", "".((isset($_POST["city"]))?$_POST["city"]:"") ."", "".((isset($_POST["country"]))?$_POST["country"]:"") ."", "".((isset($_POST["phone"]))?$_POST["phone"]:"") ."", "".((isset($_POST["fax"]))?$_POST["fax"]:"") ."", "0", "0", "0", ""); ?>" />
looking at your code example, it looks like you added the shipping 2, but not billing 2 and also add a line break, but its hard to tell.
If your still having a problem, I'll start an incident so we can debug the issue.