Pfffuuuu you get this from normal official update ? And you don't have used any cfw before ? Uhmmm... do you have used the full update or the patch? And your console is on 4.0 ? Why then he tells you that you can use 3.56 or later ? Thats not possible you can't use a older fw to install this would be a downgrade and sony don't allow a official downgrade.
Give us some basic information: Model of ps3, installed fw, what you have done at last, have you used any hb or cfw before ?