I'm having issues getting SMB file shares working over a PPTP VPN.

The server setup consists of a security device (DrayTek V3300) which passes the PPTP authentication to a SBS2003 server running RRAS. The server is the DC and provides DNS and WINS, the single NIC's name server is set to the NIC's IP (192.168...), and DHCP on the DrayTek sets the server IP as the DNS.

If I create a new VPN connection in Win7, leaving everything as default apart from the server, username, password and domain, I can:

• ping everything by IP address
• resolve IPs with nslookup using their fully-qualified name, as in nslookup fileserver.mydomain.local
• ping machines by fully-qualified name, as in ping fileserver.mydomain.local

However if I try to access a file share:

• within Explorer, I get "Windows cannot access ..." with "Error code: 0x80004005 Unspecified Error",
• using net use z: \\fileserver.mydomain.local\share, I get "System error 53 has occurred. The network path was not found."

If I add the machine name to my HOSTS file I can use the file share, which is my last-ditch workaround, but I have a number of VPN users and would rather a solution that doesn't involve me trying to hand-edit system files on computers half a country away.

If I set the WINS server explicitly in the connection's IPv4 settings I don't have to use the FQN to ping the machine, but that doesn't change anything else.

EDIT: The PC I'm having the issue on is running Win 7 Home Premium. After more testing I actually have two other PCs that work, one W7HP, one XP Home, and another Vista PC that doesn't work (not tested as much as the others), all four on the same internet connection (behind the same router). All of them were tested with a straight-forward, all defaults, new VPN configuration.