The reason I wondered about the shank being hooked up in two places properly is because it may not be pulling the fabric through in an even manner. I assume you have machine set on a larger stitch length? Maybe try it on basting length. Who knows, perhaps machine had a hiccup and is stuck on small stitching. Now I do not have Janome, does the walking foot have its plastic feet still applied on the foot bottom? Sometimes these break off if they are not made of metal? You might want to check Internet for these same problems with your machine model number. Good luck.