Ok I'm not sure where I am, but what I had to do is shoot six locks from a door and eliminate some guys, and I have to go trough the door or something so I 'grab' the door and it says something about throwing objects and no buttons needed, but what the fuck am I supposed to do here?
If I am not wrong, it's the mission where there was poisonous gas being released and so on. To throw that thingy to open the door, you must close your DS then open it again. (Did you somehow manage to skip those words on your screen when they told you what to do? I remember clearly that there were instructions...)