So I just thought I'd check here using 3 different laptops connected in turn to the same ethernet port on the router.
The BT tester and others say I'm getting just over 4Mbps down, but the ThinkBroadband tester always shows 2.4Mbps and sometimes much lower. The XP and W7 machines are consistent, the Vista machine returns slower results. At one point Think Broadband said it was only getting 600kbps.
Is this all normal, or do I have to try to fault find the Vista machine? Everything looks OK in Device Manager etc.
Also, the BT speed tester says not to test again within on hour. Is there a technical reason for this, or is it just to keep the usage down?