Bubble minSize maxSize error

by pythion

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/highcharts-more.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>
<div id="container" style="height: 600px; width: 600px; margin: 0 auto"></div>

JavaScript

$(function () {
    $('#container').highcharts({

        chart: {
            type: 'bubble'

        },
        plotOptions: {
            bubble: {
                minSize: '8%',
                //minSize: '8%', //from 8% upwards bubble 1 disappears !!
                maxSize: '40%'
            }
        },

        series: [{
            data: [{
                name: 'bubble 1',
                x: 35,
                y: 90,
                z: 51
            }, {
                name: 'bubble 2',
                x: 35,
                y: 70,
                z: 60
            }, {
                name: 'bubble 3',
                x: 55,
                y: 50,
                z: 75
            }, {
                name: 'bubble 4',
                x: 25,
                y: 75,
                z: 100

            }]
        }


        ]

    });

});