backdrop does not cover the the navigation bar

more detail issue at : http://stackoverflow.com/questions/37741689/backdrop-does-not-cover-the-the-navigation-bar-for-react-native-modalbox

This component works great until I use it inside the Navigator. But If this component is used inside the Navigator Component, then the model presented does not cover the navigation bar, where as the alert does cover it.
`render: function() {
var modalView =

  <Button onPress={this.openModal3} style={styles.btn}>Position centered + backdrop + disable</Button>

  <Modal style={[styles.modal, styles.modal3]} position={"center"} ref={"modal3"} isDisabled={this.state.isDisabled}>
    <Text style={styles.text}>Modal centered</Text>
    <Button onPress={this.toggleDisable} style={styles.btn}>Disable ({this.state.isDisabled ? "true" : "false"})</Button>
  </Modal>

</View>
return (
  <NavigatorIOS style ={{flex:1}}
  ref={'nav'}

  initialRoute={{
    component: ()=> modalView,
    title:'Photoos.Net',
    passProps:{ name: this.props.title},

  }}/>
); }});`

Start with the reproduction in the issue body and the linked Stack Overflow report, focusing on the Modal used inside NavigatorIOS. Confirm how the backdrop behaves when the modal is rendered through navigation. Done means reproducing the case and making the backdrop cover the navigation bar without breaking the shown modal behavior.