I'm not sure, but with some nocd's, you are having a message like this and it works after some tries
*not sure if I had this prob with the crack for NFUS, too*
I had this prob with Serious Sam (should be SS 2),there you are asked for cd and if you click 1,2 or 3 times on "try again"<--don't know what it is called in english! and not on "abort" you'll be able to get into the game!!
I think GLH is right with his fixed exe theory, but I'm only trying
to help