[Users] encrypted imformational exchange message is invalod because of it is incomplete ISAKMP SA

hello peoples
i am trying to connect LAN -LAN VPN from Cisco vpn concerator and Linux Freeswan  

 i just installed freeswan 2.05 on RH 9 Built 2.4.20-30.9smp everthing is installed and working fine when i start the vpn connection i get the following error
"encrypted imformational exchange message is invalod because of it is incomplete ISAKMP SA"
 

my ipsec.conf file
version 2
config setup

           interfaces="ipsec0=eth0"
           kilpsdebug=none
           plutodebug=all
           uniqueids=yes
conn vpn
          type=tunnel
          keyingtries=0
          authby=secret
           left=62.x.y.z
           leffnexthop=62.x.y.a
           leftsubnet=208.a.b.0/24
           right=212.a.b.c
           rightsubnet=192.168.a.0/24
           keylife=8h
           ikelifetime=8h
           auto=add
           pfs=yes
           
 

my ipsec.secret file
212.a.b.c 62.x.y.z :PSK "MY SECRET KEY"    

when i pass the command
# ipsec auto --up vpn
i get the following error
" encrypted imformational exchange message is invalid because it is for incomplete ISAKMP SA"
 same error in /var/log/secure and message logs  

2) we have any option where we can enter our IKE Proposal in freeswan?  

please help
thanx in advance
bhagat panwar