USB Power for modems

[vodacom3g]

Are there any changes to the suggested poll options?

1) Plug it into a single USB port using a normal USB cable.
2) Plug it into 2 USB ports using the dual-plug cable.
3) External USB powered hub.
4) I use a specially modified USB cable.

Options 1 - 4 ) I get disconnects and I'm using (insert one of the above 4 methods) to power the modem.

Options 5 - 8) I don't get disconnects and I'm using (insert one of the above 4 methods) to power the modem.

9) I get disconnects but don't believe they're power related.