I am working through an example in Beginning iPhone 3 Development and for some reason, nothing is happening when I press the buttons or slide the slider. It isn't that the slider is sliding, for example, but not doing anything. It just won't move. It is almost like the entire app is frozen. There are 2 text fields, and when you click them, nothing happens either. No keyboard popping up and whatnot, just nothing. I don't know why this is happening and I would be very grateful is you could tell me why.