Well first off, F5 is a switch so pressing it an even number of times is the same as not pressing it at all...
Second, if you can skip the intro movie, SOMETHING is working on the gamepad, unless you are using a key that isn't on the pad to skip the movie.
Third, is it still displaying and playing sound at the point you can't do anything?
Fourth, can you map the keys to your keyboard and it work?