You should be able to view the network using either Terminal Services or Remote desktop Console that comes with Wiindows XP.
We had exactly the same problem last year and took ages to sort out real head scratcher. Nobody could really answer the question per-say but we got some good pointers in newsgroups.
You have given very little information away i.e Are you doing a PC to PC VPN?, Is there a involved, what is server/PC type, remote PC operating system do you use RAS if connecting to a server etc. etc...
What we did as a workaround was to connect over the VPN and then use RDC that comes with WindowsXP even though it was a 2000 client PC we were connecting from.
Also ensure before you connect the PC to the VPN server that your PC is part of the domain.
In the TCP/IP properties of your Nic on the client point dns entry under tcp ip properties on your NIC point to yourdom.local or whatever your network name is.
First sign of troubleshooting for this type of problem would be IPCONFIG /ALL from the client after establishing a connection to the VPN --To see what IP address is being assigned.
Can you ping the server when connected to the VPN.
Check Wins Entries
HTH