I have a problem that's like this.
I've noticed that newer trainers (specifically the Deus Ex: Human Revolution and Tropico 4 ones) have been taking a lot longer to load, and then if I go and do something else while waiting for them, they crash.
It seems like you need to keep them on top and in focus for them to fully load without crashing.
This happens to me, don't see it as much of a problem though, and it's not 100% chance of it happening either. (for me)