With adaptive payments, there has to be two people in each transaction. So what you are seeing is every time a sale is made where there is no affiliate involved, then there has to be another payee or the adaptive payment system won't work. This is not something JVZoo did, this is the way PayPal coded their API for adaptive payments. So the only thing JVZoo could do was have it send the smallest amount possible to us when there was no affiliate so the transaction would go through.
JVZoo will send it all back to you, but this is completely PayPal's programming, not JVZoos. When there is a sale made by an affiliate, you won't see that as there are two people in the transaction being paid (you and the affiliate), it's only when there is no affiliate involved when you will see a small amount being taken out and sent to JVZoo.
Here is PayPal's Official explanation.