Does your machine have a good straight stitch feature for top stitching quilt tops?

[coffeebreak]

I am beginning to think you got a lemon with your 9960 with all your thread issues, tension and now not sewing straight when quilting. I have the same machine and haven't experienced any of these problems (knock on wood). If you are not buying a new machine shortly, I suggest taking your machine to be serviced.

Lemon? Wouldn't surprise me at all!