Primo Walls have always been really good and reliable tires throughout the years.
the prob is that they arent really rated for super high pressure even tho most people pump them up to 100psi+ with no probs.
it IS possible that u just got a defective tire. try re-seating it like AK said, and if the problem persists, try to exchange the tire or buy a new one.
btw...how much pressure is in the tire when it starts to bubble?
and also, do u run 2 Walls? front and back. if so, are both popping out at the bead at high pressure? or is it just one tire doing this?
and last, are u using single wall rims? single wall rims are not really made to handle high pressure tires, and a problem like this isnt uncommon with those types of rims.