running rancid manually works, but not via do-diffs

[Rizzo, Joe]

"next, I would suspect pty handling by ssh - or maybe the terminal type
it ends-up with might be affecting it?" refreshed my memory...

I set the following in bin/env
TERM=vt100;export TERM
COLUMNS=160; LINES=48; export COLUMNS LINES

The affected devices are now being polled successfully.  Thanks much
John!

FYI - here are the versions:
Redhat9 2.4.20smp kernel
Expect 5.39
Tcl 8.4.4

The device being polled is Linux system running ZebOS.