We discussed this last night, and it would appear that your problems were with IO::Tty. You are also on what you called a vanilla Unix System V, Release 4. This is not exactly the most common platform in the wild any more, and the Expect_intro documentation warns that:

BUGS
       This module has not been tested on a great variety of
       platforms and is relatively young. Interesting and
       unexpected features will undoubtedly surface.

Well that is what the test suites are meant to catch, and I am sure that Austin Schutz (tex@habit.com) will be very interested in having it pass on your platform. As I said last night, "perl -V" contains a lot of information about how your system is configured that will help them do that.

Now there is a possibility that this is a 5.005_02 specific bug, I would still try the 5.005_03 release. But my guess is that it is some surviving BSDism due to having started with a code base developed on SunOS.