It’s either me, or NetworkManager sux. This is the most incomplete and incompetent piece of software I have ever seen. The only reason I actually use it is that there is no better alternative which does whatever NetworkManager manages, somehow, to do.
My initial thought was to setup NetworkManager as the dial-up component. What should be more obvious than that? Well, it just won’t connect, and its logs are horrific at best. So back to gksudo script for us, then…
You can put this script cell.sh in /usr/local/sbin/ and change its permissions to eXecutable (by root, of course), and then add a nice menu item called “Cellular Internet” in your Gnome Menu. It should run ‘gksudo /usr/local/sbin/cell.sh‘