I misread your post as I had the same problem when I got rid of the default config, no longer an IP no MAC access and my fix was as per my response.Next I did reset configuration and I can now connect to default IP
Cannot be that as MAC access to other HW platforms is fine with the same client.Try disable the firewall in windows.
I have that to and with disable firewall con i connect
Greg has updated his already excellent guide to include dynamic addressing, I have been using this fine over a dynamic IP aDSL line.If you are running dynamic IPs, IPSec is pretty useless in MT.
Static works like a champ and is really easy. What are you trying to do?