firefox没法显示iframe _HTML/CSS

firefox无法显示iframe
废话不说，上代码
3.html:

HTML code

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="cn1949/chkBrowser.js" type="text/javascript"></script>
<script src="cn1949/short-hand.js" type="text/javascript"></script>
<script src="cn1949/string.pro.js" type="text/javascript"></script>
<title>三人行--普通提问</title>    
</head>

<body>
    <div>
    <iframe frameborder="1" name="sense" scrolling="no" src="1.html" width="200px" height="200px"></iframe>
    </div>
</body>
</html>

1.html:

HTML code


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>json-php测试</title>
</head>

<body>
<div style="width:200px; height:500px">hello!hello!hello!</div>
</body>
</html>

ie8/chrome/opera显示正常。就FF13.0.1无法显示，打开firebug：

HTML code


<div>
    <iframe width="200px" scrolling="no" height="200px" frameborder="1" src="1.html" name="sense">
        <html>
            <head>
            </head>
            <body>
            </body>
        </html>
    </iframe>
</div>

我不清楚，head/body内容怎么就被过滤掉了

------解决方案--------------------
结贴了？？hao
------解决方案--------------------
奇怪的现象
------解决方案--------------------
奇怪的现象。