readline taint screwup in mj_shell

I'm running perl 5.8.9 on FreeBSD.  In mj_shell, I can type regular text, 
but when I do a backspace or any other editing character, it dies with

Insecure dependency in eval while running setuid at /usr/local/lib/perl5/5.8.9/SelfLoader.pm line 73.

It's using the perl readline, and I have been poking at it without 
success.  When I try to run .mj_shell under the perl debugger it dies with 
some other complaint before it even tries to read anything from the 
keyboard.

I vaguely remember fixing this before, but I can't remember what I did. 
As I recall, it's a bug in one of the libraries that MJ uses, not in MJ 
itself.  Ring any bells?

R's,
John