Ralackk: If you go to the games folder look for a config or ini file with the games settings if you open it with notepad(administrator rights on win7, vista) then you may beable to manually add the 2 extra resolutions.
meudoland: ok, but question is why wasnt that implemented directly into the game?...
Answer is - It's an old game. If you work in software development (you may, I don't know), you'll notice the constant trade off of good vs sales. I suspect this was a victim of the dark lair of the salespeople. Older games had a lot smaller budgets, and people were a lot more forgiving in return, features could be left unimplemented and just esoteric knowledge of enabling then. It was before the day of - Release, patch, patch, ask the community if it's stable, patch*x, apologise, patch*x, boast about product stability - see Assassins creed 2.
In this case - I like the fact they focussed on other stuff, it's not such a bad thing to be left to others to point out.