I have one of the 570 QE machines, and I have the same problem. I think it is because of the wide space between the feed dogs. That allows the machine to stitch wider specialty stitches, but it prevents the fabric from being in contact with both feed dogs when you sew a quarter inch seam. I have resigned myself to using my walking foot to give a little more control. I don't need the wider space, since I don't do machine embroidery. For a supposed Quilting Edition, I was disappointed in some of the short-comings it has. It didn't come with a walking foot, but it did come with a buttonhole foot! I hope you find a work-around for your piecing.
Leslie