Well guys thanks for the responses. I tried everything and even took it to the genius station at the local store to check that the ethernet card wasn't bad.
It was fine. So I once again called Apple support on the phone and got a fantastic tech who knew right away how to fix it.
He said that when my old d-link router died it sent a spurious signal that corrupted my system file. Sure enough, found my system file and brought it to the desktop. He said that this makes the system file go to a default. Well Wa-La, problem solved. Working great now.
I have to say that not only is Apple support easy to reach, but absolutely fantastic to work with. My tech Chris was extremely smart, and he even was an American who spoke English and lives in Kentucky!! I'm sold on this brand after years of dealing with Gateway. Only Apple for me from now on.
Oh and by the way, kept the airport extreme router. It was expensive but is really well built.
Thanks again.
Pete