I also did that Kja,but i have another problem...When i click on native screen and launch w3 than i go on "Options" but every time i recive an "Exit Signal"o.O
And when i unmark the "native screen" it works normal,but i cant set the brghtness..
Interesting i just noticed that you can't do it when launching the game without flags. Tick the "native fullscreen" box on the launcher tab in client, right under gateways, the brightness slider will be unlocked.