it is not possible to character input in textarea in the iframe

it is not possible to character input in textarea in the iframe

it is not possible to character input in textarea in the iframe.
and if iframe outside, can be entered.

1) I enter in advance the textarea of character.
   abcdefg
2)In order to insert a character, put the insertion point between characters.
　abc I defg
3)Character in this state I can not be input.


Condition:  iOS7.1.2  (iPad)　　There is no problem in iOS8.1.1
                 jQuery 1.11.0
                 jQuery mobile 1.4.2
                 Safari






a.html

<iframe src="/textarea.html" width="100%"></iframe>


textarea.html


<html>
<head>
<title>test</title>
<meta http-equiv="Content-Language" content="ja">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv="Content-Style-Type" content="text/css">
<meta http-equiv="Content-Script-Type" content="text/javascript">
<meta http-equiv="Pragma" content="no-cache">
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">

<!-- script include -->
<script language="JavaScript" type="text/javascript" charset="UTF-8" src="/mcs/js/lib/jquery-1.11.0.min.js"></script>

<script language="JavaScript" type="text/javascript" charset="UTF-8">

</script>
</head>
<body>
<textarea data-theme="c" name="S" id="S" cols="60" rows="2" style="overflow-x: auto; overflow-y: auto; width: 100%; font-family: Arial, Helvetica, sans-serif, externalFont; line-height: 20px; height: 30px; " ></textarea>
</body>
</html>