Fixes an issue with Prestashop when people use carriers that figure cost by address, or weight. This prevents "Free shipping" from showing, unless the person is really getting free shipping. This replaces your blockcart.tpl file.

gistfile1.tpl

{*
* 2007-2013 PrestaShop
*
* NOTICE OF LICENSE
*
* This source file is subject to the Open Software License (OSL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/osl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2013 PrestaShop SA
*  @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*}


{* IMPORTANT : If you change some data here, you have to report these changes in the ./blockcart-json.js (to let ajaxCart available) *}

{if $ajax_allowed}
<script type="text/javascript">
var CUSTOMIZE_TEXTFIELD = {$CUSTOMIZE_TEXTFIELD};
var img_dir = '{$img_dir}';
</script>
{/if}
<script type="text/javascript">
var customizationIdMessage = '{l s='Customization #' mod='blockcart' js=1}';
var removingLinkText = '{l s='remove this product from my cart' mod='blockcart' js=1}';
{if !$logged or $carrier==0}
var freeShippingTranslation = '{l s='Log in to calculate shipping' mod='blockcart' js=1}';
{else}
var freeShippingTranslation = '{l s='Free shipping!' mod='blockcart' js=1}';
{/if}
var freeProductTranslation = '{l s='Free!' mod='blockcart' js=1}';
var delete_txt = '{l s='Delete' mod='blockcart' js=1}';
</script>


<!-- MODULE Block cart -->
<div id="cart_block" class="block exclusive">
	<p class="title_block">
		<a href="{$link->getPageLink("$order_process", true)}" title="{l s='View my shopping cart' mod='blockcart'}" rel="nofollow">{l s='Cart' mod='blockcart'}
		{if $ajax_allowed}
		<span id="block_cart_expand" {if isset($colapseExpandStatus) && $colapseExpandStatus eq 'expanded' || !isset($colapseExpandStatus)}class="hidden"{/if}>&nbsp;</span>
		<span id="block_cart_collapse" {if isset($colapseExpandStatus) && $colapseExpandStatus eq 'collapsed'}class="hidden"{/if}>&nbsp;</span>
		{/if}</a>
	</p>
	<div class="block_content">
	<!-- block summary -->
	<div id="cart_block_summary" class="{if isset($colapseExpandStatus) && $colapseExpandStatus eq 'expanded' || !$ajax_allowed || !isset($colapseExpandStatus)}collapsed{else}expanded{/if}">
		<span class="ajax_cart_quantity" {if $cart_qties <= 0}style="display:none;"{/if}>{$cart_qties}</span>
		<span class="ajax_cart_product_txt_s" {if $cart_qties <= 1}style="display:none"{/if}>{l s='products' mod='blockcart'}</span>
		<span class="ajax_cart_product_txt" {if $cart_qties > 1}style="display:none"{/if}>{l s='product' mod='blockcart'}</span>
		<span class="ajax_cart_total" {if $cart_qties == 0}style="display:none"{/if}>
			{if $cart_qties > 0}
				{if $priceDisplay == 1}
					{convertPrice price=$cart->getOrderTotal(false)}
				{else}
					{convertPrice price=$cart->getOrderTotal(true)}
				{/if}
			{/if}
		</span>
		<span class="ajax_cart_no_product" {if $cart_qties != 0}style="display:none"{/if}>{l s='(empty)' mod='blockcart'}</span>
	</div>
	<!-- block list of products -->
	<div id="cart_block_list" class="{if isset($colapseExpandStatus) && $colapseExpandStatus eq 'expanded' || !$ajax_allowed || !isset($colapseExpandStatus)}expanded{else}collapsed{/if}">
	{if $products}
		<dl class="products">
		{foreach from=$products item='product' name='myLoop'}
			{assign var='productId' value=$product.id_product}
			{assign var='productAttributeId' value=$product.id_product_attribute}
			<dt id="cart_block_product_{$product.id_product}_{if $product.id_product_attribute}{$product.id_product_attribute}{else}0{/if}_{if $product.id_address_delivery}{$product.id_address_delivery}{else}0{/if}" class="{if $smarty.foreach.myLoop.first}first_item{elseif $smarty.foreach.myLoop.last}last_item{else}item{/if}">
				<span class="quantity-formated"><span class="quantity">{$product.cart_quantity}</span>x</span>
				<a class="cart_block_product_name" href="{$link->getProductLink($product, $product.link_rewrite, $product.category, null, null, $product.id_shop, $product.id_product_attribute)}" title="{$product.name|escape:html:'UTF-8'}">
				{$product.name|truncate:13:'...'|escape:html:'UTF-8'}</a>
				<span class="remove_link">{if !isset($customizedDatas.$productId.$productAttributeId) && (!isset($product.is_gift) || !$product.is_gift)}<a rel="nofollow" class="ajax_cart_block_remove_link" href="{$link->getPageLink('cart', true, NULL, "delete=1&amp;id_product={$product.id_product}&amp;ipa={$product.id_product_attribute}&amp;id_address_delivery={$product.id_address_delivery}&amp;token={$static_token}", true)}" title="{l s='remove this product from my cart' mod='blockcart'}">&nbsp;</a>{/if}</span>
				<span class="price">
					{if !isset($product.is_gift) || !$product.is_gift}
						{if $priceDisplay == $smarty.const.PS_TAX_EXC}{displayWtPrice p="`$product.total`"}{else}{displayWtPrice p="`$product.total_wt`"}{/if}
					{else}
						<b>{l s='Free!' mod='blockcart'}</b>
					{/if}
				</span>
			</dt>
			{if isset($product.attributes_small)}
			<dd id="cart_block_combination_of_{$product.id_product}{if $product.id_product_attribute}_{$product.id_product_attribute}{/if}_{$product.id_address_delivery|intval}" class="{if $smarty.foreach.myLoop.first}first_item{elseif $smarty.foreach.myLoop.last}last_item{else}item{/if}">
				<a href="{$link->getProductLink($product, $product.link_rewrite, $product.category, null, null, $product.id_shop, $product.id_product_attribute)}" title="{l s='Product detail' mod='blockcart'}">{$product.attributes_small}</a>
			{/if}

			<!-- Customizable datas -->
			{if isset($customizedDatas.$productId.$productAttributeId[$product.id_address_delivery])}
				{if !isset($product.attributes_small)}<dd id="cart_block_combination_of_{$product.id_product}_{if $product.id_product_attribute}{$product.id_product_attribute}{else}0{/if}_{if $product.id_address_delivery}{$product.id_address_delivery}{else}0{/if}" class="{if $smarty.foreach.myLoop.first}first_item{elseif $smarty.foreach.myLoop.last}last_item{else}item{/if}">{/if}
				<ul class="cart_block_customizations" id="customization_{$productId}_{$productAttributeId}">
					{foreach from=$customizedDatas.$productId.$productAttributeId[$product.id_address_delivery] key='id_customization' item='customization' name='customizations'}
						<li name="customization">
							<div class="deleteCustomizableProduct" id="deleteCustomizableProduct_{$id_customization|intval}_{$product.id_product|intval}_{$product.id_product_attribute|intval}_{$product.id_address_delivery|intval}"><a class="ajax_cart_block_remove_link" href="{$link->getPageLink('cart', true, NULL, "delete=1&amp;id_product={$product.id_product|intval}&amp;ipa={$product.id_product_attribute|intval}&amp;id_customization={$id_customization}&amp;token={$static_token}", true)}" rel="nofollow"> </a></div>
							<span class="quantity-formated"><span class="quantity">{$customization.quantity}</span>x</span>{if isset($customization.datas.$CUSTOMIZE_TEXTFIELD.0)}
							{$customization.datas.$CUSTOMIZE_TEXTFIELD.0.value|escape:html:'UTF-8'|replace:"<br />":" "|truncate:28}
							{else}
							{l s='Customization #%d:' sprintf=$id_customization|intval mod='blockcart'}
							{/if}
						</li>
					{/foreach}
				</ul>
				{if !isset($product.attributes_small)}</dd>{/if}
			{/if}

			{if isset($product.attributes_small)}</dd>{/if}

		{/foreach}
		</dl>
	{/if}
		<p class="cart_block_no_products{if $products} hidden{/if}" id="cart_block_no_products">{l s='No products' mod='blockcart'}</p>
		<table id="vouchers"{if $discounts|@count == 0} style="display:none;"{/if}>
			<tbody>
{foreach from=$discounts item=discount}
{if $discount.value_real > 0}
				<tr class="bloc_cart_voucher" id="bloc_cart_voucher_{$discount.id_discount}">
					<td class="quantity">1x</td>
					<td class="name" title="{$discount.description}">{$discount.name|cat:' : '|cat:$discount.description|truncate:18:'...'|escape:'htmlall':'UTF-8'}</td>
					<td class="price">-{if $priceDisplay == 1}{convertPrice price=$discount.value_tax_exc}{else}{convertPrice price=$discount.value_real}{/if}</td>
					<td class="delete">
						{if strlen($discount.code)}
							<a class="delete_voucher" href="{$link->getPageLink('$order_process', true)}?deleteDiscount={$discount.id_discount}" title="{l s='Delete' mod='blockcart'}" rel="nofollow"><img src="{$img_dir}icon/delete.gif" alt="{l s='Delete' mod='blockcart'}" class="icon" /></a>
						{/if}
					</td>
				</tr>
{/if}
{/foreach}
			</tbody>
		</table>		
		<p id="cart-prices">
			
			{if !$logged}
			<span  class="price ajax_cart_shipping_cost" style="float:left!important">{$shipping_cost}</span>
			{else}
			<span id="cart_block_shipping_cost" class="price ajax_cart_shipping_cost">{$shipping_cost}</span>
			<span>{l s='Shipping' mod='blockcart'}</span>
			{/if}
			<br/>
			{if $show_wrapping}
				{assign var='cart_flag' value='Cart::ONLY_WRAPPING'|constant}
				<span id="cart_block_wrapping_cost" class="price cart_block_wrapping_cost">{if $priceDisplay == 1}{convertPrice price=$cart->getOrderTotal(false, $cart_flag)}{else}{convertPrice price=$cart->getOrderTotal(true, $cart_flag)}{/if}</span>
				<span>{l s='Wrapping' mod='blockcart'}</span>
				<br/>
			{/if}
			{if $show_tax && isset($tax_cost)}
				<span id="cart_block_tax_cost" class="price ajax_cart_tax_cost">{$tax_cost}</span>
				<span>{l s='Tax' mod='blockcart'}</span>
				<br/>
			{/if}
			<span id="cart_block_total" class="price ajax_block_cart_total">{$total}</span>
			<span>{l s='Total' mod='blockcart'}</span>
		</p>
		{if $use_taxes && $display_tax_label == 1 && $show_tax}
			{if $priceDisplay == 0}
				<p id="cart-price-precisions">
					{l s='Prices are tax included' mod='blockcart'}
				</p>
			{/if}
			{if $priceDisplay == 1}
				<p id="cart-price-precisions">
					{l s='Prices are tax excluded' mod='blockcart'}
				</p>
			{/if}
		{/if}
		<p id="cart-buttons">
			{if $order_process == 'order'}<a href="{$link->getPageLink("$order_process", true)}" class="button_small" title="{l s='View my shopping cart' mod='blockcart'}" rel="nofollow">{l s='Cart' mod='blockcart'}</a>{/if}
			<a href="{$link->getPageLink("$order_process", true)}" id="button_order_cart" class="exclusive{if $order_process == 'order-opc'}_large{/if}" title="{l s='Check out' mod='blockcart'}" rel="nofollow"><span></span>{l s='Check out' mod='blockcart'}</a>
		</p>
	</div>
	</div>
</div>
<!-- /MODULE Block cart -->

same here