TS-XL/R5 SSH & SMB2

[abdndamo]

Hi folks,

I have a handful of TS-XL/R5 which I have upgraded to V1.71 and due to the SMB vulnerabilities, I want to enable SMB2 per some of the guides already on here:

http://forums.buffalotech.com/index.php?topic=24630.msg88052#msg88052
http://forums.buffalotech.com/index.php?topic=24628.msg88050#msg88050

But before i do so, I need to connect via SSH.  On updating to V1.71, SSH was enabled automatically, but when I try to connect using putty, SSH connects, it asks for a username and password, entering the correct admin password causes the session to disconnect.  Entering an incorrect password keeps the session going.  So, I know my password is correct, it is just that the session is abruptly ended. 

Any ideas why?  Thanks in advance.