Vpn is it poss for 2 users on same IP?

I have a Win2K Server in the office and am accessing it remotely. My internet connection is DSL and I’m using a Linksys Dsl Router to share the connection. Well I’m finding that when I connect a session from more than one machine, my connection fails. Does anyone have any suggestions as to how I can have more than one connection from the same shared internet IP?