VPN partial connection through remote network

[SpyderX]

Hello all,

I have what I find is a strange problem. I will describe as best I can:

I am using 2 VPN routers connected using IPsec between separate networks.

I have successfully connected the two networks via VPN IPsec.

I can ping and connect via Windows sharing to multiple network sharing servers across the VPN with no problems (WinXP, and Samba).

I am unable to connect to the Windows 2003 server through the VPN, nor can I ping it.

However, when connecting PPTP (via WinXP) to the same VPN, I am able to ping and connect to the Windows 2003 server with no problems.

So it seems there is something I am missing with the IPsec configuration on one of the VPN devices, or perhaps something with Windows 2003 server itself.