Is your quilt sandwich a little baggy? It should not be drum tight. Everything should be smooth, then loosen the sandwich on either the take up roller or the quilt top and backing rollers until you can grab the end of a finger (almost up to the closest knuckle to the fingernail) with your other hand, when the finger is pushed up from underneath the quilt sandwich. You need the sandwich to be able to flex with the machine's movements so the needle doesn't have to. If the needle flexes, it may miss where it needs to be at the instant it needs to make the stitch.