If so, package ticket and STRTicket both follow package main. I generally like the core of my program at the top of the source file and refer to sub below. Until now it has always worked. Am I missing your point?

@ISA = ... is just an assignment. It's not happening until AFTER your call to new(). So there is no inheritance until AFTER all of your packages. Perhaps putting each of the @ISA=...'s in BEGIN{...} blocks will work. (Maybe putting all of the packages in one big BEGIN {...} block will work? Update: Yes, it does seem to work).