Comment 22 for bug 384344

Well, I doubt if the GSM/CDMA aspect is relevant. What's more important is that your device seems to be supported out of the box, assuming it is being detected without any configuration changes. If so, the issue is just with how NM is probing the modem. You could try reverting to older NM levels to see if your modem starts working - newer NM could have broken compatibility with your modem.

You might also want to refer to:
https://wiki.ubuntu.com/NetworkManager/Hardware/3G/Probing
https://wiki.kubuntu.org/DebuggingNetworkManager

If nothing helps, you should file a new bug.

- Naveen