to be a driver thing......no support for the usb modem, ive downloaded latest st330 drivers but still no good......i may have to bypass usb modem and use an ethernet modem instead, ethernet modems dont need a driver......bit expensive though :(
You probably can get your st330 to work - click here for more details. I have to tell you however, this particular modem has never been an easy option in Linux.
The easy way is to buy an ADSL Modem/Router. Once-upon-a-time, people would scream they couldn't afford it and for some, I appreciate that may still be true. But, it IS the easy answer to connect ANY computer to the Internet and prices have fallen dramatically. It also opens the door to using more than one computer simultaneously.
Once you have one of these, just plug into an RJ45 (network) port and Linux will self configure.