Hi, could this work on Raspbian with Vodafone Mobile Broadband K3770, HSPA USB Stick (Huawei Technologies)? (It's a pay-as-you-go service which I have topped up.)

I have the first revision Pi. I don't yet have a powered hub, trying the above steps with it plugged directly into the Pi, the device showed in the list, but gave "failed to connect" when selected. Is a powered hub all that's needed to fix this?