Why would you waste your MP on something like that when you have played ME1 already let me just say what ever choices that you make in this little comic book DLC is nothing compared to what you choices you can make by playing
the game. as for it not working i can't tell you since i didn't waste 340 MP to buy it but for the sake of trying to help you its supposed to activate before your die in ME2.
Also i just check another forum that had the same Question and some one said that you have to start a (NEW) game and it will activate before Shepard gets blown to space. If it still doesn't work it might be because you have
already played ME1 Since this is a DLC for people that don't have a saved import from ME1 to ME2. Also try reloading it if none of the above work for you then i guess you SOL
Bullets is esactly right. You don't launch Genesis manually. After picking New Game from the main menu and playing through the opening, Genesis starts automatically when Shepard is blown out into space.