[vpn-help] ikea startup: Session Management error

[mh at morxy.co.uk]

I'm running Ubuntu 11.10 and installed Shrew VPN Client 2.1.7 using  
Ubuntu's package manager (ike-qtgui 2.1.7+dfsg-1build1).

$ iked
ii : created ike socket 0.0.0.0:500
ii : created natt socket 0.0.0.0:4500
## : IKE Daemon, ver 2.1.7
## : Copyright 2010 Shrew Soft Inc.
## : This product linked OpenSSL 1.0.0e 6 Sep 2011

$ ikea &
Session management error: None of the authentication protocols  
specified are supported

Can anyone explain this error? I've tried googling and can't find any  
definitive solution or cause. I can't use the ikea access manager to  
connect to any remote VPN server, probably as a result of this.  
(Meanwhile, the same VPN server works perfectly on my Windows XP  
laptop with the same Shrew client.)