I've done this before myself...found a problem only after getting the whole thing sewn together, and taking a picture. I figured though that I'd already spent so much time on it, I would take it apart and fix it, or it would always bother me. I don't think that the sign is very apparent. But if it bugs you, you should fix it. As others have suggested, I just picked out the bad block, fixed it and sewed it back in. Mine was small so I did it by hand.