I agree that it could be the bias..one reason I asked about this is because I just quilted one exactly the same and no problems at all. But it was a panel with just blocks around that..so perhaps that is why. This one is all different blocks...oh!!!!!!! The blocks are set on the diagonal also...that must be it!!!!!!!! I am about 1/2 way through the quilt - so I will starch and pin more. Hope that will help.