Demigod account error

Ive been playing the demo of Demigod and my user name etc work fine online and also via impulse, but when I try and go online with the full game it says invalid user name and/or password...but nothings changed, Ive checked it about 10 times - Ive used the same user name and password to get onto these forums.

Does anyone know a solution as its really frustrating and I'd like to play the full game online not just the demo.

Ive just tried unistalling the demo thinking maybe thats affecting things but didnt make any difference.

Thanks in advance for any suggestions!