It could however mean that there was a problem with your payment email address on the listing.
Click sell similar and scroll down to the payment section of the form. Check it shows your exact paypal email address.
If it shows another viable email address then add it to your paypal account and the payment will complete.
If there is a typo then tell your buyer to cancel their payment. Then use the request money tab directly in paypal to raise another "invoice". Include a note of your member id and the item number so that you both have full paypal protection.