Connect Vista client to SBS 2003 VPN file share by \\server\sharename used to work, doesn't now - now I have to type IP address and that connects me to Remote Office

As recently as two weeks ago I could log-on to a VPN connection remotely using Vista or XP and then in the browser address bar type \\SERVERNAME\SERVER-FILESHARE and go right to my files. After a rogue DHCP server popped up on my small network I reconfigured some settings including RRAS. Now I have a very curious problem. NOW my XP clients connecting remotely to the SBS 2003 share must do so by typing in the private ip address of the server, typing the \\SERVERNAME\SERVER-FILESHARE doesn't work any longer.  Vista clients, however, cannot connect at all. When they type the private IP address of the server, they are instantly routed to the Remote Office site on the SBS server.

I need both Operating Systems to be able to connect AND map the file share as a shared drive. I don't want to turn off Remote Office b/c I use it for accessing Outlook while on the road. Fast answer - biggest points possible . . . please.