An Update!
Well I've been messing about with Windows 7 TCP settings, Winsock and all sorts. Trying to get the best settings etc but in the end I just reset everything to Windows default.
As I have mentioned I know I get full speed Downloads as I have opened 14 different download files and counted the total MB/s achieved
I decided that I was going to try all the UK speedtest.net sites one after the other and have now done so.
The results are truly astounding. Whether all sites are capable of testing 100Mbit connections I dont know but my download speeds rantged from 2Mbit up to 103.3Mbit.
I have found that the Lancaster server is the best to test with (in my case), followed by Kingston Upon Hull. I'm located down the south of the UK but these servers are impressive!.
The Lancaster speedtest gives me consitantly over 100Mbit (104.44Mbit actual) download with 8.59Mbit upload (I get over 9.2Mbit upload on some of the other locations).
So, if your speedtest results arent that great and your SuperHub power levels etc look fine then at least try the other server test locations.
http://www.speedtest.net/result/1713877859.png