I have a Viking Rose. I almost never use a straight stitch to quilt with the walking foot. The #17 stitch I use takes nips to alternating sides every couple stitches, but does not go backwards. Are you using an extension table? It helps to have a large flat surface. My machine sets in a cabinet/table so I am able to hand stretch & guide the quilt as it is being stitched. I also pin the sandwich & only remove a pin if it is in the path of the needle.