Same here with the think broadband speed test, when I was on Be I only ever got maximum download speeds of 8mb with a 12 mb connection. On VM 50mb I get any thing between 6mb and 20mb on think broadband but get 46mb+ on other speed tests.
They must have been plugged in to the server when they showed them using a GB connection on it. Even then they got abiout 256mbps so I guess it just shows.