Re: Red Alert 3 Resolution won't change.

I got the Mac resolution issue fixed by following steps:

1) Launch RA3

2)While on main menu, press Command + Enter( return); the game will run in smaller window now.

3) Now while game runs in smaller window, go to graphics of the game, change the resolution to desired one and "confirm" it. You will see that resolution is changed now.

4) Return to main menu, press Command + Enter( return) again to get to normal size window.

Voilaa, all set!!