You can use fork/wait system calls in a process if you don't use the $pm->start or $pm->wait* methods in it, so you can freely use them in child processes.
Comment on Re: Re: Parallel::ForkManager fork/wait caveat
Thanks dLuxx (and Aristotle). dLuxx since your monk name is very close to Parallel::ForkManager's authors name can I assume you're one in the same? If so, thanks for the module - it's going to be a great help.