the way i have heard how to fix and get seams to nest is on the 9 patch you iron the seams to go to the left of the line and then next row goes to the right. and then flips when you put the block together the seams will "lock" or "nest" into place.
Another way that is gaining popularity is pressing them open. I used to do this and had great results. but my dear old mentor at quilting lectured me in the not to press open.
Last edited by kd7kyo; 06-21-2012 at 01:16 PM.