Pat,
I had a jeans needle in it and it was dull. Not worn dull but actually had a round point on it. I looked at the others in the package and they were the same. So I put in a regular universal type and that helped a bit, but not a lot. I'll look at my needles again.
We have noticed on other Singer machines that the snap on feet tend to angle up and create a bad angle that won't walk over seams. Put on a solid ankle foot with curved toes and they do much better. That doesn't seem to matter with this one either. Perhaps being a slant shank has something to do with it.
Joe