Which version are you using?
I know I bought the steam version on sale. For some reason, the developers rolled back the version number. So if you're using the steam version you want to use trainer 01.06.2011, not 07.04.2011. The 07 trainer will crash the steam game.
I'm not sure if this helps, but I would give it a try. I run the steam version of the game on windows 7 64bit with the 01.06.2011 trainer and it works great.