I've created a new mission and I've bound the action to different joystick button, but with the same result.
In the control options menu there are two alternatives;
Communications menu - which works fine, and
Microphone button - this is the one that doesn't appear to work, I've bound it to a button on my joystick and when I press it I can see the button on the throttle go in and out. However it doesn't call up a menu.
Any thoughts ?