Increasing the emitRate of a running particle emitter is buggy

import QtQuick 2.2
import QtQuick.Window 2.1
import QtQuick.Particles 2.0
import QtQuick.Controls 1.1

Window {
    visible: true
    width: 1000
    height: 1000
    color: "black"


    ParticleSystem {
        id: ps
        anchors.fill: parent

        ImageParticle {
            id: p1
            source: "qrc:///particleresources/glowdot.png"
            anchors.fill: parent
            color: "#0b471e"
            alpha: 0
            colorVariation: 0.3
        }

        Emitter {
            id: logoEmitter
            anchors.fill: parent
            emitRate: v1.value
            lifeSpan: 750
            size: 100
            endSize: 2
            sizeVariation: 80
        }
    }
    Column {
        Slider {
            id: v1
            value: 0
            minimumValue: 0
            maximumValue: 10000
            width: 300
        }
    }

}