Thanks for the fast replies! I have tried to add a photo to show where the feet are breaking, but can't seem to "get it". They are breaking in the back of the foot where the quilting guide inserts. I have another single stitch foot for my old Singer, and it has a hole in it where the quilting guide attaches. These ones have a sort of a slot instead, and the edges of the slot break out - sorry - I'll go back to Janome to check out whether this was actually their brand.