had the same problem with my pfaff quilt expression 4.0 and discovered I had put the bobbin casing in wrong so the thread underneath bunched up. I have had a few of other problems mentioned in this forum but have always solved these as it s always user error. I love this machine and have learnt a lot from it. happy quilting
Last edited by shayles; 05-25-2012 at 01:13 AM.