That kept happening with my Pfaff Passport 2.0. It would just start to stitch and the only way I could stop it was to pull the plug. I brought it in to the repair person. He said he could find nothing wrong with it and had set it up and stitched on it for quite a while. He said the he thought there might have been a tiny speck of dust somewhere in the inside that was tricking the computer or sensors or something like that it was supposed to run. He said that he had cleaned the insides really well . I have it sitting in my sewing room and have not tried it again as I have other machines... (well I did have other machines until the Viking D1 screen froze last week and the Bernina 570 started jamming again) I bought a new Viking Topaz 40 to replace the D1 and am working on trading the Bernina 570 in after the tech said they would do that. Still waiting to hear the offer and also find out what machines are available. I have ordered an insert for my cabinet for the Topaz. So my sewing studio is in disarray at the moment.