Rangy selection issue in iPad with iframes

HTML

<script src="http://rangy.googlecode.com/svn/trunk/dev/rangy-core.js"></script>
<script src="http://rangy.googlecode.com/svn/trunk/dev/rangy-cssclassapplier.js"></script>
<p>Test this text with Rangy Text selection</p>
<button>Highlight Selected Text</button>
<div id="generateFormDiv"  style="display:none"><iframe height="200" class='myMask' width="100%" id="additionalFeaturesFrame" frameborder="0"  src='/CobaltBlueDW/zHR8s'  onload="checkIframeLoaded(this)" onreadystatechange="checkIframeLoaded(this)" style="display:none" scrolling="yes"></iframe></div>

CSS

p { padding: 30px; }
chucknorris { border: 2px solid red; }
.myMask{
    width: 316px;
		-webkit-overflow-scrolling: touch;
    -webkit-box-pack: center;
-webkit-box-align: center;
display: -webkit-box;

		overflow: auto;
}

JavaScript

$(function() {
    $('button').bind('click touchstart', function() {
      var cssClassApplierModule = rangy.modules.CssClassApplier;
      var wrapper = rangy.createCssClassApplier(null, { elementTagName: "chucknorris" });
      wrapper.toggleSelection(window);  
    });
});

checkIframeLoaded(null);
function checkIframeLoaded(obj) {
alert('called');
document.getElementById("generateFormDiv").style.display = "block";
 var iframe = document.getElementById("additionalFeaturesFrame");
 var iframeDoc = null;
		var iframeState = null;
			iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
			iframeState = iframeDoc.readyState;
      iframe.style.display = "block";
      }