*whew* I thought
you were wearing the FB from your post title, lol.
Have you used Oxyclean in the wash? Oxyclean will break down PUL. I did it to two FB's and a Bummis.
Also, I have found that vinegar is hard on covers too. Not everyone believes this, but my nyklon covers started breaking down when I started using vinegar in the rinse cycle.
Hope you can figure it out. Leaky dipes are a PITA!