Thanks for that information!
The extended fields for the shipping is showing correctly, let me try to explain what the "Extended" and other pieces of the line item mean:
Under "Each" you will see the original price ($6.80 for example), and under "Discount" you will see the discount. In this case, since the shipping is fully discounted, you should see -$6.80. This means the "Extended" will be $0.00, since the customer pays $0.00 for shipping in the end.
Similarly, an item with "Qty" 2, and "Each" of $29.00 will show $59.00 in the "Extended" for the final amount the customer paid for that line item.
Please let me know if you still have questions regarding the "Extended" part of the order's line item!