[Zope] Persistant Zombies and a sanity check

I use htmldoc to generate pdf documents connecting to Zope via a simple popen2() call in an external procedure which pipes input to htmldoc and grabs output from htmldoc. The htmldoc process remains in the process table as a zombie and remains there until Zope is restarted. To avoid persistant zombies, I'll need to not use the factory function, popen2, and do a bit closer management of the process--that is, the parent will need to iexecute a wait on the child (htmldoc) so that when it completes the child process can die. Am I missing something? -dra