I sent of a mail to p5p and perl-ithreads today regarding threading issues. I hope that might clarify abit about the problem of sharing variables between ithreads.
I guess the big question is, should perl automaticly lock shared SVs so you don't coredump if you don't, or should it not. I am not sure but I think I agree that perl should never coredump because a user made an misstake. Or is it better to coredump than to produce confusing results?