Things I have tried.
1. remove, redownload and retry ME2 trainer
2. Remove, reinstall ME2 and all DLC
All other trainers work fine, this is the only trainer that does not play a sound when a key is pressed. I select F1, tab out of the game and see the confermation on the trainer it is enabled. The issue is you cannot have the tendancy to press the wrong buttons, or you have no clue what cheat you have enabled or disabled.
Again, All other trainers do not have this issue, and I have deleted via the game trainer manager and had it redownload the mega trainer.
If I ever get it working I will hopefully be able to remember how I did it. Other than that the trainer works fine