Faye, could it be this design? Some are just not digitized properly. You mentioned doing three others that turned out okay; I wasn't sure if they were different designs or three of this same one. When I have a problem with embroidery, I check (in order): threading, correnct stabilizer, new needle, different top thread, different bobbin thread. If none of those solve the problem, then I adjust top tension, but not the bobbin case. Last resort, I take my machine in, and there's usually a burr or a very small piece of lint that's in one of the tension disks. Good luck!