I just rebuilt my windows 7 laptop using our new corporate laptop image, and now from time to time when switching networks or when going offline (walking to the train) I get the Working Offline popup asking me if I want to connect or try again.
Unlike most people, my problem isn't that I'm "stuck" in offline mode, I simply never ever ever want to be in "offline mode." If I try to open a webpage when I'm not connected, I just want a regular 404, not some change to my system to start displaying me cached webpages.
I've found no way to just turn this feature off completely, or any indication as to why I get this message now when I've never had it on earlier machines/instances.
I also already have SP1 installed, as some have said that there was a fix that might have resolved this issue in SP1.