thats a question for your internet provider, nothing to do with your hardware also, try finding a speed test site which is in the uk, rather than the Netherlands!
something usefull to add this time do you have an external router? if so maybe try rebooting it. mine does a similar thing after say a week it'll just slowly grind to a hault. reboot and all is well. also are there other people using it at the same time as you?
post #1: reset and changed to the spare newer model. I've reset it and conected just the slow comp to it with a good cat 5e 2m cable, no difference. Still 15x slower than the old comp at the end of 20m of cat5.
gotta be an issue with the internet service then, either that or the speed site you went on calculated your speed wrong
UPDATE: out of all the people i know most computers get between 550 and 2000 Kbps with speedtest. However two computer that i know of (my fast AMD one and a mate that has an AMD processor machine) both get 12,123 Kbps. Is there something special that means AMD can get much more out of a Gbit LAN connection i wonder? It's not just the speedtest, actual file downloads are 10 - 15x quicker.