First I generally echo Corion and Jeffa's comments, but of course that doesn't help you with the immediate legacy problem you are faced with. Based upon some cursory analysis of the posted material, I would guess the error lies in the printheader routine; this routine either lies in another file or has been truncated from this one. Can you post a fresh node that contains this subroutine?

I note that your error arises in the context of an eval. The only posted eval could not give rise to the fatal condition you posted, so it's coming from some unposted code. I suspect someone is doing a bait-and-switch with autogeneration of subroutines, but I can't be sure without seeing where it's coming from. Perhaps if you grep your scripts for the words sub printheader, though they might be doing the name assignment to the symbol table directly ($::{printheader} = ...).

Regardless, it feels like someone has dumped too much cleverness on your lap.