Mass Effect 2
Make sure you have the the 1.2 game patch installed or maybe reinstall the patch to see if that helps with anyone having problems.
AVG is the worst anti-virus ever seen, get a decent one! I suggest Kaspersky or avast!
Anyway, great post HonestGamer, though I have to say I've never had a problem using the trainer with DLC's - I have every ME2 DLC released to date installed with the 1.2 patch, and I've never found the trainer to be non-working. It must have something to do with individual system configurations rather than the game.