Volume doubles after unmute

import QtQuick 1.1
import QtMultimediaKit 1.1

Rectangle {
    width: 360
    height: 360
    Text {
        id: label
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }

    Audio {
    id:muzik
    volume: 1
    source: "audio/muzik.mp3"
    muted: Qt.application.active ? "false" : "true"
    }

    Timer {
    id:soundRestartTime
    interval: 10000
    repeat: true
    running: true
    onTriggered: {
        muzik.position = 0;
        }
    }

    Component.onCompleted: {
        muzik.play();
    }

    MouseArea {
        anchors.fill: parent
        onClicked: {
            Qt.quit();
        }
    }
}