Hah I saw that thread and I was already wondering if it was the same problem.
Will people from outside the LAN still be able to connect like they can currently?
And since you can't enter port ranges at the Virtual Server page, is that list extendable? Because I have the server side of a server/client app running on the same machine, and it uses quite a few ports.
I'm not a D-Link employee but I can answer your questions for you.
First a question. You mention using several ports but I'm assuming that you aren't requiring port redirection. The virtual server is used to allow incoming ports to be redirected to both an IP address and a different port.
Say you have a website called "http://mywebsite.com" but in order for your customers to access the site through your router they have to type "http://mywebsite.com:8888". Your router recieves the incoming request at port 8888 and then it forwards the packets to your web server at port 80.
If you are requiring a lot of port redirects, then that is something more along the line of a commercial grade router.
Now, what I suspect is that you need port forwarding in which incoming ports get redirected to the same ports but to a certain IP address. With port forwarding you can assign groups. If that's what you need, then make sure that you assign a DHCP reservation to the server.