you changed the cart to be stored in a cookie instead of a session.
the view cart button is triggered on the WA_Store_Cart_Items session being set:
<?php if(isset($_SESSION["WA_Store_Cart_Items"]) && $_SESSION["WA_Store_Cart_Items"] != "") { ?>
<a href="<?php echo($assumedRoot); ?>cart.php">View Cart</a>
<?php } ?>
if you change the cart to be stored in a cookie, no session is set.