Hey,
I have same problem trying to connect my ADSL modem to the LAN port on my Airport Extreme Base Station, all I get is 'searching for PPPoE host', yet if I connect directly to my PBk - no problems. I tracked down the thread below which seems to suggest that the upgrade to 10.4.2 solves the problem, can you shed any light ?
http://www.macworld.com/forums/ubbth...b=5&o=&fpart=1