sound like it's time to re-thread both top and bottom, check and see if the spool is on correctly... these machines CARE which way the thread comes off and you will have to look at your book to see which is correct... then make absolutely sure you have the presser foot in the DOWN position.... another common problem for thread-nesting... and finally, the bobbin case must be threaded properly and balanced with the top thread... I simply sew with the same thread...it's so much easier to make sure the stitch is balanced... using the professionally threaded bobbins with the tiny thread for FMQ just doesn't like it when i try it...