Network Settings For Pppoe


I've been using PPPoE to connect to the internet via a DSL modem since 1999. My ISP is SBC/Yahoo (formerly pacbell), and I'm running OSX version 10.2.8 on an old 400 MHz iMac.

Recently I've had problems with the Network control panel settings. When my computer tried to connect to the internet, it would fail at authentication. When I open the Internet Connect app, it shows the proper settings, including what I believe is the correct password-- it's masked, but it's the right length (and it works sometimes). However, when I click the "Edit" button that takes you to the Network control panel, the password in the PPPoE tab is different. I can change it there, but when I press the "Apply" button, it reverts to the previous password! Extremely frustrating...

In the past, I have usually been able to get things working eventually by messing around with it-- turn off the remember password, apply the settings, restart Internet Connect-- but I haven't been able to figure out the exact sequence of actions that leads to success. And in the last couple of days, it has become completely hopeless; I have been unable to find any way to get to work, after spending several hours messing with it. It always fails at that authentication step.

A friend at work suggested that there was some script or ini file that holds network settings, buried somewhere deep in the operating system. He suggested that I find it and delete it, and then reenter the settings manually. Is this a good idea? Where might that file be? Any other ideas?

Thanks much!