With stunning regularity, all the trainers I run crash on the first startup. Second startup usually works, but sometimes it happens twice or more in a row.
It appears to happen during the authentication phase of unlimited only trainers. I've tried making a keyfile so the trainers don't have to authenticate online, but they still crash.
This is one of the errors: Unhandled exception at 0x004085a2 in trainer.exe: 0xC0000005: Access violation writing location 0x00000000.
Any trainer that needs authentication has crashed on me. It seems to be the authentication itself, regardless of the version or type of trainer. Specifically this has happened to trainers for: Alice - Madness Returns, Duke Nukem Forever, From Dust, GTA4 (original and liberty city), Hard Reset, Mass Effect 1, Mass Effect 2, Star Wars Force Unleashed 1, Star Wars Force Unleashed 2.