After I defeat the Joker, the trainer causes the game to crash. I had the same problem in October of 2011. Apparently this has not been fixed yet. I'm using the most recent version of the trainer for the Steam client on my second play through. Any help would be appreciated.
Thanks!
This has happened a couple of times for me too. After you defeat the last henchmen and hit the Joker a couple of times turn the trainer off and beat him normally. I did that and the game continued normally for me.