Xeon, did you send in a template? Does your piece have pleats? The only reason I can think as to why you have ripples is that the piece was made based on measurements and not a template with your unique contours. The contour of your head should be used to make the correct pleats by the makers. The piece should fit nice and snug. Are you stretching in certain areas when you attach? That might cause it too.

On a side note, your piece looks amazing, I didn't even realize you had flaps!. The blending on the sides is perfection. Can you post a pic that shows the outline of your lace from hairline to flaps and then to the sides?