I did have this problem in my DS,due to a sway back/hollow.larger buttocks, and I kept on decreasing my dart in back waist,thats all I can remember really with that problem.Just kept tweaking away, and finally managed to get it close,I did increase my darts to accomodate around the waist also,lots of tweaking in the past on that issue.Dont get dispondent it will happen for you im sure.