Because we get no orders in get orders call. From what we have read over the forums it seems that you need to link ebay and paypal accounts first.
When is order created ? when the item is payed or when the checkout is complete ? If when the item is payed then ..setting the item as payed on the sandbox page works. But setting the thing as payment received on the sellers end doesn't change it's status ... We have many items with checkout complete and 1 even payed(don't know how it happened) but getorders still returns no results..