We've recently moved to Team System and now a remote team needs access to our source. However, they use a different IP address to access the Team System server, and whenever they try to open a project, they are prompted to check out and change the project. Is there a way to work around this? It seems to be the 'SccAuxPath' property which is the problem.
EDIT: I found this article which explains that there are three ways to support distributed teams using TFS - VPN, reverse proxy, and a hosted solution. I'm accepting Jason Whitehorn's answer as he's suggesting the first option, VPN, which seems the best. If this isn't possible for us I'll suggest the reverse proxy option.