Windows 7 desktops experiencing delays with SSH

Issue

• Testing indicates that the logon delay problem is affecting ALL of our RHEL servers at our producition site, but strangely it seems to be only the Microsoft Windows 7 desktops that are affected. Windows XP seems unnafected also.

• We have made no changes to our network configuration.

• The SSH client (Tiny Term) would sit there for about 30-60 seconds after username and password are supplied and appear to 'freeze', however if the user just leaves the session it will eventually log on, once logged on the user is able to do their normal duties.

• Windows Server 2008 with the same SSH client has no delays at all in logging onto the RHEL server.

• Also, tests from other RHEL servers on network also experience no delays.

• I have looked into the logs on the RHEL server's affected and there is nothing unusual to report, no spamming, no excessive network traffic.
  Just the normal logon and logoff traffic.

• We are using DNS to resolve server names, but if you use the IP address of the server to connect from a Windows 7 desktop, you get the same problem occuring.