I had had shredding problems since around Thanksgiving. I met the owner of the company that makes my machine and he offered to come to my house to fix it! Do you think that machine would shred ONE THREAD? NOPE, Nada, NOTHING! (I was mortified! lol!) He DID however find a big glob of oily lint lurking in the bobbin raceway. Took him about 15 mins to find it. When I had had time to recuperate from the 4 days at the quilt show, I replaced the needle (had the wrong kind in there..mortified AGAIN! See a pattern here? lol) I tweeked the eye of the needle and VOILA! No shredding! Guess what I will be trying next time I have shredding problems? Hope you find your culprit...its a mystery you have to solve!