I got this game working fine in a custom res 16/9 mode. 16/10 isnt working without stretching.
Firstly make sure to run the game normal first,
Then change res to 1600x900 to tell the game to use 16/9. (its the only native widecreen res available)
Then quit, do as Racer_S says
Download this:
http://dl.tocaedit.com/ureschanger2.zip
Install to your PoP folder.
edit resolution.ini
enable ForceViewport so it reads
ForceViewport=1
set your resolution width/height and save the file
I set up a custom 16/9 res for my monitor (in nvidia control panel). Width=1152 Height=648 so I used this in the resolution.ini file.
Make sure "Aspect Scalling" is on in Nvidia control panel (sorry dont know bout ATI)
And run game.
Works great. correct FOV, only slight letterboxing top and bottom of screen, because the games 16/9 on a 16/10 monitor. Also movies are stretched, but hey its the gameplay that really matters.
Thanks to Racer_S for this tool.