Some USB mobile broadband devices are not identified correctly in Ubuntu. This is because of a feature that allows them to appear as USB storage devices to install drivers in Windows and Mac OS. Try unmounting or ejecting the device by right clicking the icon on the desktop and selecting Unmount or Eject.

If your device is still not recognized, you can file a bug against the udev package using the following command in terminal:

                
                  ubuntu-bug udev