OVRInput.Get(OVRInput.Button.One) not ever returning true

The button presses in my code aren't being recognised on any of the devices despite having the OVRManager script on my OVR camara rig, and the grabber and grabbable scripts working fine on the objects I've created. Here's a stripped down class that has OVRInput.Get(OVRInput.Button.One) never return true. Pressing Keypad8 does have the desired effect.

public class Football : MonoBehaviour {

    private Rigidbody rb;
    public float Force = 1600;

    void Start () {
        rb = GetComponent<Rigidbody>();
    }    

    void FixedUpdate () {

        OVRInput.FixedUpdate();

        if (OVRInput.Get(OVRInput.Button.One))
        {
            rb.AddForce(Force * Time.deltaTime, 0, 0);
        }

        if (Input.GetKey(KeyCode.Keypad8)) {
            rb.AddForce (Force*Time.deltaTime,0,0);
        }
    }
}