i worked for almost 2 1/2 weeks trying to solve my issue with Ghost Recon Future Soldier no playing in full screen and it turns out i needed to adjust my TV to a different zoom to play it full screen... what a NIGHTmare THAT was to figure out.
USUALLY if there is no solution, or NOONE is having a similar problem (as w/ me and GR-FS) it is a setting or something specifically related to you, your computer settings, or TV settings.
hope this helps