Since Paypal's updates last Friday we have had some ordering problems. Paypal assures me they are working on the problem. Orders are going through, but receipts are being delayed getting to the customers and the instant download links aren't getting sent for some. We will send out the download links manually if this happens to you. We have extra help to help fill orders quickly until Paypal gets itself debugged.
If it has been more than 4 hours (during business hours) and you haven't received your download links, email into email@example.com and let us know.