Forgot about that. You're right.
So the problem is on that computer and if you are not losing the connection, it points to a software problem rather than hardware. Software doesn't get borderline senile and just occasionally forget stuff on its own. Something is causing the settings to repeatedly become corrupted. If it happened just once, it would be a hiccup. A recurring problem would suggest some kind of conflict or incompatibility with other software, or a bad software install.
Think back a year to when the problem started. Around that time, did you install or update anything that has Internet hooks? (If you go to Uninstall or Change a Program in the Control Panel, the list of everything installed includes the...