thanks for the replies. i do cut a big X on one side ... although it
seems to matter also how deep you cut them. if you don't cut deep
enough, you don't get thru the inner skin. if you cut too deep, when
you try to squeeze them to crack them open, they just split in half
instead with the inner skin stuck on.

so far, my best success has been with broiling for a few minutes (5
seemed a bit too much, with a bit of burning and smoking), then cooking
covered with a couple spoons of water for another 15 minutes. problem
is, i think because the inner skin peels away from the nut, the nut
ends up drying on the outside into a hard rind. any less though, and
you don't get that nice, cooked, soft, starchy nut.

point is, i don't think the big ol' X is enough in and of itself.
again, i just wonder how they did it in taiwan ... i don't think they
even put an X on the nuts, and they all just popped open easily.