Re: Problems with connect to client Networker
I don't think that disabling GSS authentication will help here, as for NW 8.x nsrauth is required in order to work with client wizard (and other features).
I think this is more related to certificates (peer information) as pointed already, so please, make sure you delete the peer information of server on client, and of client on server.
Also make sure that DNS and/or hosts file is configured correctly, and also check if on the client side there is any firewall (if Windows then OS firewall could be an issue. Also make sure UAC is disabled, at least for testing purposes).