Cant access drives on windows 2000 VPN

I am using windows 2000 server to accept incoming vpn connections. It is a single homed box with a private IP. I have a netopia cayman 3500 router that I allow vpn passthru to the server. From my home I can connect to the server with my user name and password and I see the PPTP connection on the server, however I cannot access any of my shared drives. I tried to connect using the servername and/or IP address of the server with no luck. I cannot even ping the server. I am assigning a static IP range thru windows 2000. The client is windows xp that is behind a linksys router.

Any help would be appreciated

Dale