Hey David
Had something similar, have a VPN router (Linksys RV042) as opposed to your VPN server. Also use PPTP for the setup. Have four people that tunnel in, no one can see shares. Nature of the beast what would solve this problem is setting up a WINS server, but for what we are doing it just does not justify.
The good news! You should still be able to target your other computers and networked printers. I just have short cuts set up on the remote computers try targeting one of the computers you can't see via IP address one of mine would be \\192.168.90.20\ (use Explore) this would show all the shares available on that computer from there just drag one of the shares to your desktop and create a shortcut. The printers are a little different do the same thing drag the printer to the desktop it will prompt you to download the driver (providing it's a printer attached to a PC) after it gets its driver it will place itself in with the rest of your printers and you can delete the shortcut off your desktop. All of what I described can be setup off site just need the IP address of the machines.
Ex:
\\192.168.90.20\Documents (shared doc folder on PC)
One other thing notice I'm using 192.168.90.*** as opposed to the common 192.168.0.*** or 192.168.1.***. I'm going to assume you have some sort of private addressing going on like me. The reason is if one of the remote computers is on a Lan with the same addressing scheme it might cause havoc with shortcuts. So try to make your addressing scheme somewhat unique.
Hope this helps .
John