This is probably one of those newbie mistakes, but I am making a basket-weave scrap quilt with flannel backing and the flannel seems to be stretching while I quilt it. I am using my walking foot and doing a basic stitch in the ditch along the seams (which is another story, I can't seem to stay in the ditch!). When I turn the quilt over to look at the back, I have folds at every intersection. What am I doing wrong? :-(