As the current code capture the exception and does not give much output, can you run the following code and post the detailed exception info?
transport = paramiko.Transport(host, 22)
transport.banner_timeout = 5
transport.auth_password(user, password, fallback=True)
BTW, does your download script work on a steelhead? if yes, can you post your solution at the
other thread? that way other people can benefit from your experience