I've had this problem for a while, but with 1.2 imminent, perhaps I can
get help.  Our internal network includes an IBM mf connected via an
Apertus gateway.  The stock tn3270 program allows me to bring up the
login screen, but when I key in the first field and hit enter, it core
dumps.  The Apertus folks said something about "not respecting packet
trailers" or some such.  However, the X Consortium X3270 program works
great.  FWIW, here's some tn3270 info:

$ gdb /usr/bin/tn3270 tn3270.core

GDB 4.11 (i386-netbsd), Copyright 1993 Free Software Foundation, Inc...
(no debugging symbols found)...
Core was generated by `tn3270'.
Program terminated with signal 11, Segmentation fault.
#0  0x1008406e in ?? ()

As always, thanks!
-- 
I don't speak (or work) for the Baltimore County Public Library.
They keep telling me, "Shhhhh!"