Hmmmm.....I recently had the same problem with long skipped stitches in spots. Tried everything....cleaned the race, changed needles, rethreaded top and bobbin, took deep breaths, sew and un-sew, over and over. Even though I didn't come to a conclusion as to what the problem was, I finally worked through it, but it was making me crazy!! Never thought about the spray basting. My problem spots MAY have been where there was a little more spray than necessary???