I think you also might be confused about the router setup. I think you might be using one router, the two diffrent ip's come from the fact that each port on a router has a diffrent IP. Say you have a two port router. Port A is the connection to the internet with an ip of 10.0.0.1 (lets say) and port B is the connection to your internal connection 66.218.71.198 (yahoo's ip). This would explain why your getting two diffrent IP's, the star might have something to do with passing through the router. Not really sure though.

DeafLamb

EDIT: by the way, i read the man page on traceroute and a couple of tutorials I googled, couldn't find anything about one star. Hope someone has the answer.