SBS2000 VPN Issue

[gorryjohn]

I am running Small Business Server 2000 and I am trying to connect to our terminal server via VPN. I have followed the SBS2000 VPN instructions including ISA Server setup guide. I can connect to via VPN and obtain IP address from pool of addresses setup in RRAS. However I cannot ping server (or any other computer on internal network), I cannot obtain a list of Terminal Servers, and generally cannot do anything on the internal lan. When I look at the VPN connection on the client, it shows bytes sent increasing, but bytes received stays at 348 bytes. If I ping the client from the server, the bytes received will increase, although the ping will timeout with no reply.
To make matters worse, this setup used to work. It just decided one day that it would stop working.
Server Setup
SBS 2000 (network setup as per 2 NIC setup guide)
Internet setup as per Internet Connection Wizard SBS2000
Static IP from ADSL ISP
Internal NIC IP: 10.0.0.2
DNS: 10.0.0.2
WINS: 10.0.0.2
When I ipconfig /all on server the settings are as follows.

Ethernet adapter LAN:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) Server Adapter
Physical Address: Omitted
DHCP Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 10.0.0.2
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :
DNS Servers . . . . . . . . . . . : 10.0.0.2
Primary WINS Server . . . . . . . : 10.0.0.2

Ethernet adapter Internet:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) PRO/100 S
Physical Address: Omitted
DHCP Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : ***.***.***.***
Subnet Mask . . . . . . . . . . . : ***.***.***.***
Default Gateway . . . . . . . . . : ***.***.***.***
DNS Servers . . . . . . . . . . . : 10.0.0.2
NetBIOS over Tcpip. . . . . . . . : Disabled

PPP adapter RAS Server (Dial In) Interface:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : WAN (PPP/SLIP)Interface
Physical Address: Omitted
DHCP Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 10.0.0.250
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . :
DNS Servers . . . . . . . . . . . : 127.0.0.1
NetBIOS over Tcpip. . . . . . . . : Disabled

To my mind the only thing that looks out of place is the DNS on the PPP Adapter. I am not sure if it is meant to be 127.0.0.1 or 10.0.0.2, which would make sense to me, but I am not au fait enough with DNS settings to make the call. RRAS is setup to obtain DNS settings from the internal adapter so it should be 10.0.0.2.

Can anyone help me with what the problem might be??

Cheers

JG