Fedora :: Firefox Sets Itself To Work Offline?

I don't start a network connection when my machine boots FC11 64 bit. When I start the connection and the Firefox browser, I always find that Firefox has set itself to work offline. I use File->work offline and uncheck that box. This fixes the problem, but only till the next reboot. Even if I exit Firefox "in an orderly manner", the next time it will have set itself to work offline.

I had this problem in previous Fedora versions. I read about two solutions on the web. One was to write a script that removed a file called extensions.cache before Firefox ran. The other was to type about:config in the address bar of Firefox, acknowledge the warning message, and use the right mouse button to togglethe value ofoolkit.networkmanager.disable from "false" to "true".Are either of these good solutions? What exactly does "network manager" do? I think of it as the gui under System->Administration->Network, but it must be more.