yes. You need to follow the batting instructions on the maximum distance. Those squares are way to big to leave unquilted. THe maximum distance is in all directions, even on the diagonal. Sounds like you didn't stabilize the Tshirts first? How did you baste the quilt sandwich? Have you tried a walking foot? Another thing you might want to try is put a piece of wrapping tissue paper over the area and sew right thru that. Unless you quilt really heavily, you should be able to easily rip it away. I would experiment a bit with some of the left over tshirt fabric.