After only having had my NEW quilt on my bed for one week, I popped it in the washing machine (delicate setting, as I do all my other quilts) and all the vertical machine stitching came undone. After wondering and considering most everything that could cause this, I realized that I recently organized my threads and remembered finding a bobbin in the thread box with slightly glimmering thread. Still wondered where and what I used this for. Now I realize I put it there for a reason............ it was wash-away thread and when I re-organized the threads I must have moved it to the bobbin holder. In future I will definitely label the bobbin..... what a bad way to learn a lesson!!