Hello Vicki,
If you have checked the stitch length, if you have checked that there is enough pressure on the foot and they are both okay then look at the teeth to see if they are coming up above the slots in the throat plate, if they are not, check and make sure the throat plate is on properly, if that is okay then check to make sure you have not put the drop feed down.
Ken
drivewithken@blueyonder.co.uk, July 2007