For the past few weeks I have been living in a remote area of the Philippines where the only option for internet connectivity is the mobile broadband service provided by a local cell-phone company (Huawei Mobile E158). As you, I have been pulling at my hair (and I donít have much hair left!) for the past few days attempting to get connected through my Linux OS, Mandriva 2010. I will here relate, in general terms, my ultimately successful experience.
First, I discovered I needed additional software. Fortunately, a friend had a Win7-based machine on which I downloaded rpm versions (and subsequently installed from a thumb-drive to Mandriva) of: COMGT; LIBPCAP0; & PPP. Additionally, but perhaps unnecessarily: KPPP; KPPP-PROVIDER; AND USB-MODSWITCH.
Second, the following website was extremely helpful, especially in setting up the broadband usb drive to behave as a modem only: http://linuxph.wordpress.com/2010/09...-linux-mint-9/
Third, I had to specify dev/ttyUSB0 and setup Analog Telephone Modem (POTS) (pppO).
Now I am able to connect, as root, at my machineís Network and Internet Connection Management icon (right click).
Wishing you the best, ~rc