If your survey matches that of the walkthrough exactly and the game is not registering it as correct, then there must be some answer on the survey where you did not do what you were supposed to do within the game in order to arrive at the answer, or something isn't typed exactly right into the survey. I wish I could be more specific than that, but it's impossible for me to know exactly what that might be.
There are a lot of good threads on HeR Interactive's forum about this part of the game. Here is
one of them. There are many others.