when you say "nests" do you mean blobs of thread that clog the machine?
or do you mean it makes a bit of a blob on the back side of the piece at the beginning of the seam?
mine does that, too.
it used to drive me crazy because it doesn't look neat and tidy.
then i realized that it does keep the seam from coming apart at that end.
once the piece is done, that odd little knot doesn't show or create any problems as construction proceeds.
sooooo ... i'm training myself to ignore it.
