it goes to the part of the block that is orange and blue with the Yellow triangle.
I'm not sure, but I will mess with this technique also, but if you only sew the first diagonal and cut apart, then put the resulting square together with the yellow ... do both diagonals you should end up with exactly the block you were going for ...
but don't quote me on that, I will have to work on it at the post. (unless I happen to find it before I leave <g>)