I had loads of problems with just this sort of thing earlier this year--here's the thread Installing Expect.pm and IO in which a lot of talent looked at my problem. I believe the consensus was that I (and you) might be one point revisions down from a distribution with a good IO::Pty and IO::Tty.

Good luck--that project is back at my old job. I didn't get a chance to finish it, so I don't have a certain solution.

By the way, a descriptive subject line might get more help.