Okay, on my last play through, I missed the big materia you get by stopping the train. I did get the other three, though, but for someone reason I didn't receive Bahamut Zero. So at the dig site I was looking for the Midgar key, and actually dug up Bahamut Zero!! What is with this?! Is the game glitched or something? In all my playthroughs I have never encountered something like this!