You're actually supposed to go into the move from being upside down. Here's a girl who is getting into it correctly (she doesn't allow embedding but you can go to YouTube): http://www.youtube.com/watch?v=e2T5XvgdvIY As you can see by her attempts, it's VERY challenging!
I am extra bruised and battered from trying this trick over and over. Still haven't quite mastered it. But there will be much celebrating when I do!!