In my experience, that was the solution. I run the game and find that the text from briefings and other things (map editor, and the battle list has a problem at the beginning) do not show in the screen, i mean, you only see the game´s background, but not the text. I found that when i jump to desktop 'via' ALT+TAB or Windows key (from keyboard), and then, i switch again to the game, this text appears now as it should do. Now i must say which computer or O.S. i use. Pentium Quad 2.4, ATI HD3870 and Windows XP SP2.
I hope you can find a solution and continue playing this. (God!, i was almost a year without playing it because of the drivers)