I really did RTFM and I googled. I queried perlmonks!! One waits in vain for Burner-Lees semantic web when I can better find answers like this.
I really wish I had some advice to contribute back. Likely I don't!
Ah yes I do : be careful with Apache::Session. if you use Apache::Session with File, and you set a directory for it to keep its session data in, make sure it exists or else it hangs without explaining why when you start the server. Use File not Semaphore locking as we seemed to get deadlock with semaphores.