[cflsystems]

The file is product.tpl not products.tpl
Also your cart version is 4.1.9, main 4.2.1
You just have to move the code around - you can use Webmaster to find out which templates or Firebug in FF
You will be looking for something like this in your product.tpl code

        <table cellspacing="0" class="product-properties">
          <tr>
            <td colspan="2" class="product-subtitle">
              <div>{$lng.lbl_details}</div>
            </td>
          </tr>
          <tr>
            <td class="property-name">{$lng.lbl_sku}</td>
..................................
.................................
                    {$lng.txt_product_downloadable}
                  {/if}
                {/if}
              </td>
            </tr>
          {/if}
        </table>