Why is it that Crysis 2 keeps stating that I have an invalid serial code even though it's valid?

Why is it that Crysis 2 keeps stating that I have an invalid serial code even though it's valid?

Try this one: http://www.gamesas.com/forums/viewtopic.php?p=242726#p242726 if it doesn't help just contact the EA support as they as the publisher are responsible to take care of this kind of issues.