Simply download this: https://app.box.com/s/xi8j786ymxmxzyeon8hw9oj4v71vptwy
or
https://drive.google.com/file/d/1u1RjHyjKwQ9hkAR-ulhtrmbSQhQ7aRi_/view

After that, go to C:\Program Files (x86)\Steam\steamapps\common\Operation Flashpoint Dragon Rising, and replace OFDR.exe with the file from that download link.

Special thanks to ACiDxCHRiST from the original Steam forums for creating the fix during his spare time back in 2011.

Now enter the game and adjust the resolution past the cap, and voila! Beautiful graphics at your disposal!