I have an 13+ year old hand me down kenmore machine.
I put it on zig zag to practice satin stitching... which wasn't turning out well and not entierely my fault, I think my machine is screwy.
So today, I switch it back to straight stitch, go to sew and BAM, broke the needle. The thing was still zig zagging, even thought I'd turned the dial to straight stitch. I had to monkey with the dial back and forth a few times and it finally started sewing straight when I set it to straight.
Weird.