I actually finally got FPSC to work at 1920 x 1080, and this works for both test games and built games. Only problem is the HUDS don't stretch out to fill the screen.
You can try saving your changes in the setup.ini and then restarting your comp. I believe this is what I did to get the values to be changed.
Another thing you can try, is to maybe search your computer for another setup.ini that FPSC might be using and remove it.
"Dad? Dad, I'm a- Ye- Not a "crazed gunman", dad, I'm an assassin! ...Well, the difference bein' one is a job and the other's mental sickness!" - The Sniper.