QGLCamera rotation

I’m using the QGLCamera class to setup my viewing. When the user rotates the view with the mouse, i use the method QGLCamera::tiltPanRollCenter to rotate the view. The problem i get is that i cannot seem to limit rotation to just tilt and pan even though i pass in 0.0 for the roll parameter. E.g. camera.tiltPanRollCenter( mouse_y_angle, mouse_x_angle, 0.0f ); How do i limit rotation to just tilt and pan without any roll?