Sounds like that Neural Net can't learn anything. Even if the weights are being modified during the learning procedure, each perceptron in the layer will be outputting the same value to the next layer, thereby removing any learned behavior. Essentially, the network will act as a simple adding machine where the result is scaled by the learned weights.
...I think, I never really learned much about neural networks.
And JC, stop getting other people to do your homework.
