I was just about to write and say: that's no Thiers, that's a Dovo... but then I read your post. If you are absolutely sure the stone is flat (try it on a marble tile or something else you know to be flat) then you should send the blade back and get a replacement .... (have you tried laying it on the other side? do you see that it rests on the toe and heel but is up in the middle? Have you lapped your hone properly? so many questions)