I've tried the latest Widescreen Fixer and Flawless Widescreen and neither registers the game as even running.

I have the up to date MW3 Steam version and would love to be able to play it on my 3 screen Eyefinity rather than just 1. (I've also made sure to follow the directions on the main page for it on here, seeing image to Native etc.)
WSF doesn't see the game, doesn't enable, and just crashes... FWS never sees the game running apparently.)
Any help with this?

(I know the game has been out for a couple years now, but I want to play through it before I play Ghosts. I haven't played a COD game since MW2 and Black Ops.)
Thanks!
(Eyefinity is setup and working fine. It's just the game I'm having trouble with.)