IonRangeSlider problem with updating values

Setting just the 'from' value sometimes fails; setting both 'from' and 'to' works, but the 'to' shouldn't be necessary.

HTML

<link rel="stylesheet" href="http://ionden.com/a/plugins/ion.rangeSlider/static/css/ion.rangeSlider.css">
<script src="http://ionden.com/a/plugins/ion.rangeSlider/static/js/ion-rangeSlider/ion.rangeSlider.js"></script>
<link rel="stylesheet" href="http://ionden.com/a/plugins/ion.rangeSlider/static/css/skin1.css">
<div>
    <input id="range_01" />
</div>

<a href="#" onclick='setSliderFrom();'>Set from</a>
<br>
<a href="#" onclick='setSliderFromTo();'>Set from and to</a>

JavaScript

$("#range_01").ionRangeSlider();
var slider = $("#range_01").data("ionRangeSlider");


// Set the min, max, and from.
// The from value is 9 less than the max.
setSliderFrom = function() {
    var n = Math.floor((Math.random() * 100) + 1);
    slider.update({
        min: n, max: n+99, from: n+90
    });
};


// Set the min, max, from, and to.
// The from and to values are 9 less than the max.
setSliderFromTo = function() {
    var n = Math.floor((Math.random() * 100) + 1);
    slider.update({
        min: n, max: n+99, from: n+90, to: n+90
    });
};