Probably because the game was patched two more times in the last 24 hours and yet another new trainer is needed.
PWizard and Caliber thank you all for all the hard work you all do for the community. I just wish you all could get to enjoy the games for yourselves a little bit more without everybody always complaining about a trainer not working. Come on people, before coming on here and complaining about the trainer not working or it crashing your game to desktop see if the game was updated. The guys/gals at CH also deserve a chance to try and play the game. Yeah, I know that you paid for a trainer but complaining about the trainer because there was a new patch put out is not the end of the world for you. Play the game without the trainer for a while you may enjoy it. It does seem to give you a little more gratification for playing without the trainer sometimes.