Well they just released an update on Stream and of course the trainer stopped. update 3
I just about broke my G19 keyboard over my knee... after my 300th death on "Loose ends" on the hardest difficulty (when phantom enemies shoot around corners in groups of 90 or more at a time) I decided to take the plunge and get a Cheathappens membership so I could put bullets in eyeballs while in god mode and bullet time. First I downloaded the promo trainer, verified it worked, shut down MW2 and purchased the membership.
I downloaded the newest trainer, started the game back up and in the time it took me to do that... steam updates the game without any interaction from me in any form. No, "There is a patch available and it is required to play online, would you like to install it?" They just hijack my PC and do what they want without my permission.
So I have now disabled the evil "we-will-update-what-we-want-and-you-can-suck-it" option in steam and I will have to wait for a new trainer to be released... talk about the worst luck in the history of gaming...