"Junk data left to incoming packet buffer after all data processed"

[Phil Pennock]

[ After looking over the openssh.com website, this seems to be the list
  to use, including for OpenBSD users?  I've subscribed. ]

I'm using OpenSSH_2.5.0 as currently found in OpenBSD's OPENBSD_2_8 CVS
branch.  I'm now finding a strange error when I try to su, _within_ the
connection.  The client side is _not_ OpenSSH.

Every single time that I type "su -", and local echo is disabled, after
typing the second letter of the password I get:
 Local: Junk data left to incoming packet buffer after all data processed
and the connection is closed.  Cue putting a console on the box to get a
root prompt ...

Hopefully I haven't just revealed exactly how the root password starts
;^)

When I use "ssh -v" I get no extra information.

The client is running protocol 1.5, and is derived from the SSH.com
product.

Can anyone please say authoritatively if this is a client bug, or if the
server is sending back bogus data?  If there's any extra diagnostic
information needed, let me know how and I'll be happy to co-operate.

I'm looking towards migrating a number of service machines towards an
OpenSSH based system; having problems with the currently deployed client
will be a major hindrance.

Thanks,
-- 
Every program has at least one bug and can be shortened by at least one
instruction -- from which, by induction, one can deduce that every program
can be reduced to one instruction which doesn't work.