Well, now you've got me curious!! A question--- When you seam your pieces are you using a consistent seam width (that famous scant 1/4") and then are you always pressing to the dark fabric? Then when you turn one set around your seams are on opposite sides and if you put a pin through the seams to correctly line them up when you stitch, your pieces should match up correctly in the middle. I think when you're talking of points matching you mean the center where the seams all meet. Sorry to go on about this but I'm puzzled why it isn't working for you.
Winnie