This must be a contagious problem - machine flu maybe?? I did some fsl ornament covers a week or so ago with no problem. When I went to do something else on my embroidery machine, the top thread kept getting caught on the wrong side of the hook on the bobbin case, causing nesting and then freezing up, giving me a safety warning. So I took out the bobbin case and cleaned it - could see no dust, but the brush picked up quite a bit. I brushed and brushed, then put it back together, changed the needle, and the problem was fixed. Amazing what a little dust in the bobbin case can cause !