Connecting to Internet

This is a new problem for a system that has performed flawlessly for several years.

I returned from a trip to my brother-in-law's house with this problem. I was using their household wireless connection, sharing it with–GASP!-a motley collection of PC's! Now, my airport does a nice job connecting to the internet . . . BUT-elements in the bowels of the system persist in searching for a PPOE server, which clogs up the works till the search is abandoned. I get notice that this search fails and then the system renews its efforts. Definition of insanity, I suppose, played out before my eyes. I select "Disconnect Built-In Ethernet" line from the menu in the tool bar each time a search for PPOE begins and the process will quit eventually and then everything's fine.

Thanks,
Lenny Hoy