I have a Huawei E156G modem (local service provider is Mobitel).
As some of you probably know, if I boot my laptop with the modem already plugged in, it connects successfully. Sakis3g also proves useful. However, somewhere along the sakis connection process, it appears that network manager barges in connects the modem itself.

The weird part is that I have another Ubuntu desktop. The software and updates are almost identical on the two machines, but the modem just refuses to connect on the desktop. I've tried sakis, USB-modeswitch and booting up with the modem plugged in.

In the end, I would like to know how to set up USB-modeswitch (I tried it once then uninstalled because I ran into difficulties) and also why the modem works on only one of my PCs (hope I didn't jinx it )
If it's any help, I've found out that the kernel is supposed to switch this particular modem correctly by itself.