When copying the trainers to MyTrainers I always give them (the EXE) the name of the game. As it happens sometimes (the ones I tried) they have the same name as the game EXEs. So how should the trainer find a game when there is another EXE with the same name - namely itself - in the process list?
Renaming the EXE of the trainer and voilá... Everything works fine.
All times are (GMT -08:00) Pacific Time (US & Canada). Current time is 3:21:44 AM