Ok just to let you all know I have the game downloaded from D2D and it is working perfectly! Absolutely fantastic!
I should make you all aware however that I had to change my location to US in Windows in order to activate the game.
I have been doing a bit of reading and apparently Direct2Drive made a bit of a mistake. The game was only supposed to be downloadable by those in the US until Friday. However they did not put in the warning at first and for a few hours they allowed international users to download without any warning or issue. This is why I saw no mention of a US only download and had no problems despite putting in my location as UK.
Since realising their mistake they implemented the US only thing and put in the warning which is what you guys were seeing when trying to download it. Some of you got around it by changing your location to US.
Unfortunately once the game is downloaded and unzipped you also have to activate it and this checks your location. All I did was change my location to US and everything went smoothly and the game is now running. If this doesn't work for you then there is another workaround which I am 100% sure works as it has been discussed in depth on other forums but I am hesitant to mention it here as I am not too sure about OcUK's policy regarding this method. For the record it is not illegal or copyright infringement but I would still not like to take that chance.
As a side note for anyone who after downloading cannot get it to work, Direct2Drive are offering refunds straight away due to it being their mixup. You can email their tech support by going here:
http://support.gamespy.com/article.aspx?id=10600
And clicking the "send request" button.
In all honesty had I known about all this hassle I wouldn't have pointed the D2D thing out to you guys at all. But I truthfully had no idea that this download was only intended for those in the US since at the time they had no mention of it on their website and definately no warning during the purchasing and downloading procedure. I sincerely apologise to anyone who is annoyed over this but as I said, I had no idea, I thought I was doing you all a favour.
Good luck guys. If anyone is having trouble getting their copy to work feel free to email me and i'll see if I can help, though I won't be able to reply until tomorrow afternoon. Worst case scenario is that you will have to wait until Friday then your D2D versions should work fine.