When you do a search through the affiliate sales stats you are only shown stats on sales made directly through affiliates. Sales made by the seller will not be included. Sales that have resulted in a refund will not be counted.
To obtain more accurate stats go to the Sellers tab in your JVZoo account. Under the Sellers tab click on the Actions button for any product then select Detailed Sales. Here you will see the detailed stats on your own product(s).