When I launch/play Far Cry 2 the screen is offset (not centered with the monitor). I have tried adjusting the settings in the game itself, but the problem still remains. It is the only game I have with this problem.

Any answers or suggestions?

Definitely going to need more information than that.

To start off with, looking at the software side of things, what screen resolutions have you tried and what is your monitor's native resolution? Are you using DirectX 9 mode or DirectX 10? Is your DirectX library actually up to date? You can do this using the Microsoft provided redistributables from their download pages. Which version of Windows are you using and have you tried compatibility modes and running as administrator, etc?

Next up, hardware. What hardware do you have? GPU, monitor (or indeed multiple monitors), etc.

Probably a good idea to contact GOG support, too, and provide them with a DXDiag file. Instructions for doing so are on their support form here:

http://www.gog.com/support/contact/technical_issues_with_games/far_cry_2_fortunes_edition

I'd go with the graphical/visual issues option for this particular issue you are having.

Are you running a dual monitor setup, or have the second monitor turned on in Windows video properties even with no second monitor attached?

Ran auto-adjust on the monitor... problem solved. I feel a little silly, but again, only game I had to do it with.

Was the game using different resolution and/or colour depth to your desktop then?