Sorry, I forgot to mention that I did try $|=1 already. It doesn't work!

Doesn't work how? What is it you're expecting to happen that didn't happen?

I'm starting to think my perl install is messed up.

I doubt your install is messed up. You could try export  TERM=dumb   test.pl

Are there any unit tests I can run?

Sure, but they're not usually installed. You could verify your install with perlivp, but I doubt that'll help with this problem.