Zen Cart is installed on the main directory. There is a blog in /wordpress. In order to display some blog thumbnails on the ZC site, as per this the following was added to the html_header above <!DOCTYPE html>:

PHP Code:
<?php 
require('wordpress/wp-blog-header.php');
?>
The following was added to the pages I wanted the blog posts to appear on in ZC:

PHP Code:
<?php
// Get the last 12 posts.
global $post;
$args = array( 'posts_per_page' => 12 );
$myposts = get_posts( $args );
foreach( $myposts as $post ) :    setup_postdata($post); ?>
<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>" target="_blank">
<?php the_post_thumbnail(  array(480, 320) ); ?>
<br />
<?php the_title(); ?>
</a></div>
<?php endforeach; ?>
It actually works quite well!

Then I noticed that orders dropped off since this was done about a week ago. Did a test order and found Total: $0.00 on the checkout_payment page and checkout_confirmation pages.

Debug logs:
---------------------------------------
[08-Mar-2016 21:39:33 UTC] PHP Warning: Invalid argument supplied for foreach() in /site/includes/modules/order_total/ot_group_pricing.php on line 66
[08-Mar-2016 21:39:33 UTC] PHP Warning: Attempt to modify property of non-object in /site/includes/modules/order_total/ot_tax.php on line 26
[08-Mar-2016 21:39:33 UTC] PHP Warning: reset() expects parameter 1 to be array, null given in /site/includes/modules/order_total/ot_tax.php on line 26
[08-Mar-2016 21:39:33 UTC] PHP Warning: Attempt to modify property of non-object in /site/includes/modules/order_total/ot_tax.php on line 45
[08-Mar-2016 21:39:33 UTC] PHP Warning: Variable passed to each() is not an array or object in /site/includes/modules/order_total/ot_tax.php on line 45
---------------------------------------

I would like to have both the blog excerpts via the code I had working, as well as the Total price in the checkout. Can someone please point to what was wrong and/or causing the Totals to turn to $0.00?

Thank you