Comment 240 for bug 868034

Try this (it worked for me with ubuntu 12.04 64 bits):
1) using gedit create a text file with the following commands:
          modprobe -r option
          modprobe -r usb_wwan
          modprobe -r usbserial
          modprobe usbserial vendor=0x12d1 product=0x1003
2) save it anywhere (I've saved it as /opt/modem.sh)
3) asign execut permission
4) in a terminal type: sudo gedit /etc/rc.local
5) add the following lines at the end of the file
           /opt/modem.sh ## or the path and name you choosed for your file
           exit 0
6) save and exit
7) reboot
8) try your modem