Failure to receive new order email notification

I am using the Shopp plugin with PayPal checkout and sometimes new orders will not show up in my Dashboard (Shopp – Orders) nor will I get an email copy of the order. It will be as if the order never took place, however, the order does go through on PayPal and I receive the transaction details when I login to PayPal. The problem is that the PayPal Transaction Details only lists the name of the product and the quantity, but not the size or style number ordered. Can someone please help me? Has anyone else had this problem? Is PayPal or Shopp responsible for the issue?

Thanks!