I just sent him an invoice directly from my Paypal account. He sent a payment that seemed to be linked to an old email address from ebay, the email seemed to have come from Paypal. We will see what happens.
I had that problem, payments sent to my old email. I emailed the buyer and asked him to cancel payment and resend it to my new email.
You have to make sure the correct email address is punched in when you list an item to sell.