Using VPN routers to connect two offices

After a lenghty discussion and some digging my doctor wanted to connect her two offices with a vpn to securely share some files. However she did not want to incur the cost of a new server to do this.
After reading I found that I could use two linksys vpn routers to do this.

Sadly even after talking with linksys about this the vpn still will not connect. One end the router is idle and waiting for a connection the other will not connect. Anyone have any ideas? We are using xp pro as the clients.