At last, and after a long wait and suffering each time I need to use my 3G modem (plug in, plug out, use another USB port, switch two modems …etc), and the worst was that I didn’t know why it wasn’t getting recognized by the network-manager SOMETIMES!
The solution is simply installing the “usb-modeswitch” package; “sudo apt-get install usb-modeswitch“, as indicated in the following bug report, I totally agree with the bug author that the “usb-modeswitch” package should automatically be installed with the network-manager.
Note: I don’t know whether you just need to restart the network manager “sudo restart network-manager”, kill the nm-applet “killall nm-applet” and then reopen it “nohup nm-applet &”, or even restart the whole OS for this to work immediately, you can simply restart the OS, this will definitely make it work :), I’d love to read your comments and what you experienced
Just Some Techie Notes! 