I added a new user in the local database for ipsec. Clicked Activate and save. Then firewall rebooted with the following error :
Last Restart: 2010-04-07 21:30:46: pm_util.c:3716 SshPmUtil ssh_pm_make_sa_outbound_rule Verified expression failed: (&remote_ip)->type == (SSH_IP_TYPE_IPV6)
It seems like a bug in firewall software....