glad you fixed your problem but I've found with my machine I always have to do a bit of the tester before I get back to work on the quilt after changing the bobbin. My machine just doesn't like the change sometimes. I'm into the swing of it, but it does mean breaking the top thread for no reason which I don't like. Funny, I don't change any settings, just stitch a bit to get the kinks out and it fixes itself. How crazy is that? It's not a computerised machine either!