I am also getting these errors in my log file.
PHP Notice: Undefined variable: Taxes in /var/www/vhosts/domain.com.au/httpdocs/webassist/plugins/shopping_cart/cart_editable.php on line 135
PHP Warning: mysql_free_result() expects parameter 1 to be resource, null given in /var/www/vhosts/domain.com.au/httpdocs/webassist/plugins/shopping_cart/cart_editable.php on line 135