vodacom3g
Vodacom Representative
I can see how that might help the speed, but it still doesn't explain the disconnecting. And surely if the speed is only as fast as USB2, they should've taken that into account and used a different kind of port?
The problem is not the speed of USB, but rather the amount of power available on one USB port. Thus Huawei supplies a double USB-plug cable so the modem can get enough power.
In some cases we've seen the modem runs low on power and disconnects. Obviously signal conditions can play a role (and often does), but by using one of these cables at least you'll ensure enough power as well as being able to lift the modem to get better reception.