The error message states that there is a firewall mismatch and so check if you have multiple firewalls enabled.If so make sure that only one firewall is present.also try uninstalling and reinstall the the cisco vpn client.
Use the following link to get more info about reinstalling the vpn client:
http://www.cisco.com/warp/public/471/vpn3K_uninstall.html
Think this will resolve the issue.It will be better if you can provide the logs containing the error message.