My AeroPress Original chamber has developed crazing. What happened?Updated 10 months ago

Over time, the material we used prior to July 2014 in the manufacture of the AeroPress Original chamber occasionally developed crazing and stress cracking.  This is primarily a cosmetic defect and should not affect the performance of the product.  The stress cracks are not gouges where plastic is being removed from the chamber wall and pushed down into the coffee.  Instead, the plastic has gradually warped into ridges which have crevices between them.  Those are what we call furrows.  The plastic is not shedding and getting into the coffee.