The only thing I could think of is what Terri suggested. You might just want to sew the quilt pattern on the block itself before you sew applique it over the old one. Then you can just take some small stitches to secure it in place instead of actually quilting the whole block and haveing a double design on the back. So sorry you are having this problem. I have a lamp behind my machine too and hadn't thought of that happening. Good luck and let us know how you solve this.