I have the same machine and noticed that I have to hold the top and bottom threads VERY tight when I first start to sew. This is difficult with all the bulk from the rolled up quilt. Pull the top and bobin threads out about 12 inches to make sure one doesn't pull away when you start. I wrap the threads around one finger to make sure I don't lose them. Hold them tight and take your locking stitches. After I pull up my bobin thread and knot I don't cut it off--I hold them tight and take a few more stitches. Also make sure the "Fix" button is off before you start. I know someone will say this is a waste of thread but it's better than bird's nests-lol! I"m still practicing FMQ but this was one of the problems I was having, too. I wish sometimes I had a third hand to hold the thread while I held everything else in place. Just something that works for me--try it; I hope it works for you.