You can use your walking foot to SID just go slow. Either way you can't
go too fast, I think.:) About the puckering...how did you baste your quilt?
Did you have your backing taped to the floor or clamped to a table? Also,
when you SID, did you start in the middle and work your way out? You
know...center-East, center-West, center-North, center-South.
Hope this helps.