Not that the loss of ~50 euro isn't annoying but also for the sake of others I attempted to contact the administration of the site about somebody buying coins with a stolen paypal and i had my money taken back due to it. I contacted them but haven't received any response :\
This is the only email that I have: "apparently order ID 03960 was paid for using a stolen paypal account, thought you should know this."
We have had a few situations like that before, and ALWAYS it turned out that it was f* Paypal reverting the funds for no reason (oh yes, they "thought" that it got stolen).
Did you try to contact the buyer at all? He is a respected member of BitMarket and I am sure it is just Paypal acting up as usual.