I am not much of a coatings expert, but I would guess that your shipping was from an ill-prpepared surface, trying to cure the PC too fast or at too high of temperature.
Of course, we all know that you ride like a maniac. :ohmy:
Has anyone looked into having a frame blued (like a gun barrel)? Several of the fancy Baja racers do that to their frames if they don't want to leave them bare.