OpenSSH_3.5p1 server, PC clients cannot connect

[John Mendenhall]

I have setup an OpenSSH_3.5p1 ssh/sftp server on my
SunOS 4.1.4 box.  I can ssh to it just fine.  The problem
is SFTP from certain clients.

I can SFTP to it using my OpenSSH_3.5p1 sftp client.  I
can SFTP to it from MacSFTP from MacSSH.org, version 1.0.5.
However, I have several clients that cannot connect.  I have
had them try CuteFTP Pro v2, v3, WS_FTP Pro v7.62, PuTTy
pSFTP.  None are able to connect.

WS_FTP Pro gives the error:

  Failed SSH Key Exchange

PuTTy gives the error message:

  Fatal: unable to initialise SFTP: could not connect

CuteFTP just seems to hang there.

I have turned on DEBUG logging and they each appear to
stop at different places.

I did some searching and increased the Login time from 2 minutes
to 5 minutes.  No change.  I turned off PrivSep.  No apparent
change.  Compression is still on.  I run the daemon with '-u0'
to stop DNS lookups.  I have included my config
file below my signature.

Does anyone have any idea what I could be doing wrong?  I would
really like this to work for my PC/Win clients.  Please let me
know if you need any additional information to diagnose these
clients.

Thank you very much in advance.

JohnM

-- 
John Mendenhall
john at surfutopia.net
surf utopia
internet services


-----  sshd_config  -----
#       $OpenBSD: sshd_config,v 1.59 2002/09/25 11:17:16 markus Exp $

# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options change a
# default value.

#Port 22
#Protocol 2,1
Protocol 2
#ListenAddress 0.0.0.0
#ListenAddress ::

# HostKey for protocol version 1
HostKey /usr/local/etc/ssh_host_key
# HostKeys for protocol version 2
HostKey /usr/local/etc/ssh_host_rsa_key
HostKey /usr/local/etc/ssh_host_dsa_key

# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 3600
#ServerKeyBits 768

# Logging
#obsoletes QuietMode and FascistLogging
SyslogFacility AUTH
#LogLevel INFO
LogLevel DEBUG

# Authentication:

#LoginGraceTime 120
LoginGraceTime 300
#PermitRootLogin yes
PermitRootLogin no
#StrictModes yes

#RSAAuthentication yes
#RSAAuthentication no
#PubkeyAuthentication yes
#AuthorizedKeysFile     .ssh/authorized_keys

# rhosts authentication should not be used
#RhostsAuthentication no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no

# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no

# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes

#AFSTokenPassing no

# Kerberos TGT Passing only works with the AFS kaserver
#KerberosTgtPassing no

# Set this to 'yes' to enable PAM keyboard-interactive authentication
# Warning: enabling this may bypass the setting of 'PasswordAuthentication'
#PAMAuthenticationViaKbdInt no

#X11Forwarding no
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#KeepAlive yes
#UseLogin no

# 20030219 jem turned off Privilege Separation for Putty pSFTP to work
#UsePrivilegeSeparation yes
UsePrivilegeSeparation no

PermitUserEnvironment no
#Compression yes

#MaxStartups 10
# no default banner path
#Banner /some/path
#VerifyReverseMapping no

# override default of no subsystems
Subsystem       sftp    /usr/local/libexec/sftp-server