Magento order with parent item and child item instead of only child item

Question

i recently discovered a issue with some of our orders. We have configuable products with simple products as childs, selectable via one attribute.

Example:

Configurable product: 
#362, Oriental Tea

Child Products:
#180, Aroma Bag 20g
#181, Aroma Bag 40g
#972, Caddy 40g

The sizes are the attribute to select in the configurable product. Until last week, when a customer chosed a child product, let's say #972, the order information in the backend showed this child product in the ordered items table like this

Ortienal Tea, Caddy 40g
SKU: 12345

In the database at the 'sales_flat_order_items' table only one row with the according child product was shown for this order.

Now we have several orders where it seems like the customer somehow have ordered the configurable item with the child item as an option. in the ordered items table it looks like this

Oriental Tea
SKU: 12345
Size: Caddy 40g

And in the database there are two rows. The configurable product AND the simple product with the id of the configurable product as parent_item_id.

Unfortunately this also affects the price calculated by magento for this product. No matter which size the customer selects he will always get the price for the first child item.

Can someone explain whats the basic difference between this two types of orders of the very same product? Thanks a lot!

Answer 1

in general, it means that your product order from simple product page at frontend. Please check your "Visibility" attribute at product settings and change to "Not Visible Individually" to fix this issue.