Fortigate D60 (Cisco VPN Client) connects and disconnects directly

Hello,

I am facing an issue with the "Dialup - Cisco IPsec Client" feature on a new D60, with Firmware version: v5.4.0,build1011.

I connect with VPNC on my Ubuntu 14.04, and the connection is being setup successful from my laptop, but disconnects right after, every time. I tried all kinds of settings on my laptop, but it doesn't seem to make a difference. Changing my credentials will not login at all, so it seems that the successful setup is authenticating etc, but afterwards it runs into a problem.

Does anyone have an idea?

Kind regards,

Mick