I finally got up the nerve to make OBW and's actually found it to be surprisingly easy...I love it. As Forest Gump said about life....OBW's are like a box of chocolate, you never know what you're gonna get. But, now to my problem....a couple of my blocks think they are skull caps...all puffed up in the center where the corners all meet. I took them apart and re-sewed them...same result. The triangles are the same as all the others and the seams are all 1/4" in width. What did I do?