I know this sounds like a dumb question but you are entering the letters in uppercase aren't you?
It can be quite anal (the game that is) if you dont.
Also try swapping O for 0 (and vice-versa).
Hope that helps buddy :good:
EDIT: Take a look at the disc aswell as it may be printed on there (mine is)
hm, tried the JGCTH-3N3VF-GU8R2-2EM79-W3TZ7 key but no success. I read the whole 20 pages of the manual and could not find the online key. In one page it says "enter the online serial key provided with the game (only required once)"