Thank you for your reply.
No, I do not have a joystick plugged in, but a driver could put the chaos ?
....
I just watched, I have a xbox360 controller compatible (not connected) with Masahiko driver. Looking into the properties of the controller I have a Madcatz controller driver and a driver of HID game. Disabling the HID controller I can play ARMA.
So case solved
Bye