The recipe for PB in my Time-Life book on French Provincal Cooking specifies that when rolling out the dough for PB, it should be 1/8 inch thick. And when pricked with a fork, the tines do NOT penetrate all of the way through. I've been pricking my dough all of the way through and it's been rolled out thicker. Hmmm, perhaps that's why it cook up with leakage. What happens with a PB rolled thicker than what it's supposed to be?? FWIW checkout this thread concerning quiche crust.