Try this one:
Port Forwarding instructions & Triggering for the Linksys BEFSR11 Static IP Address guide & click on your Operating sytem version. eg: See win XP then click on that.
Are you using USB or Ethernet with your Linksys router??? Ethernet would be much more prefered c/c it's faster & USB can draw either or both power from your pc & also processing power which can slow your pc down!