Here's one that stalled for maybe as much as 5 years. I didn't really know why, but when I got it out because my niece was expecting, I realized that the problem was a block I just didn't like and was probably too lazy to switch out at the time I was first working on it. It was a relatively simple thing to remove the offending fabric (life-like ants on a baby quilt - eeeew!) and switch it with the airplane on the second row, left.