http://66.102.7.104/search?q=cache:3qQl9flOtrEJ:perl.plover.com/FAQs/Buffering.html+stdout+perl+flush+buffer&hl=en

Here's a good article on buffering. "Suffering from Buffering." (I sent you a copy from the google archive since it seems to have been taken down.) In the last few paragraphs it mentions that if you use the file or IO module, you can use the flush() command.

I'm not exactly clear on what autoflush does either.