A payment with "Unclaimed" status usually indicates the payment was sent to an email address which is not associated with any PayPal account yet. Go to your Seller Admin > Edit Profile and make sure your PayPal Email setting matches the email address you use to log into PayPal or a secondary email you've added to your PayPal account -- note that we would have cleared your PayPal Email setting as soon as PayPal notified us it didn't match up to any account at their end.
To get the Unclaimed payment directed to your actual PayPal account, you may simply need to add that payment's receiving email address to your existing PayPal account. If you need further assistance to claim the wayward payment, contact PayPal support at 1-888-221-1161. As soon as PayPal notifies our system the payment was claimed and completed, we will process the order as usual.