Hey!
I have exactly the same problem! I've tested and Arma is fully installed and ready to go, but when try to start it, the start screen comes visible and the play button is grey! I'm totally confused...
After that if you click the "X" to close window there comes a message "Arma 2 has stopped working". I live in Finland, and i bought it last weekend and it should be pretty "new in town" game.
Help me!
Zladek loosing his mind...