If it did anything more than just crash, I would have put up the error message.

Windows says that Perl performed an illegal operation (invalid page fault in perl56.dll)...

No, you didn't give the error message until now. And "crash" doesn't imply that the operating system popped up a window.

An invalid page fault is basically a bug in Perl. It would be good to report this using the perlbug script. Your script that produces the problem is already pretty small. What is missing so that the bug fixers can reproduce the problem is a small script that sends packets to those sockets in a way that triggers the fault.

The pseudo fork() in ActivePerl is quite new and so finding bugs with it is to be expected.

        - tye (but my friends call me "Tye")