I would test going to the actual page. I personally never use the preview tab since browsers support multi-tab interfaces.
But, I added the iframe snippet to a GCB and then placed the GCB into a page and everything works fine for me. I used a template that is barebones to make it easy to see the source. I also tried with the sandbox attribute and that worked good too.
Code: Select all
<!doctype html>
<__html lang="en" class="no-js">
<head>
<meta charset="UTF-8">
<base href="http://www.NothingHere.....ToSee.org" />
<title>Site Title</title>
<meta name="Robots" content="noarchive, nofollow">
<link rel="icon" href="favicon.ico" type="image/x-icon">
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
<link rel="apple-touch-icon" href="apple-touch-icon.png">
<link rel="canonical" href="http://www.NothingHere.....ToSee.org"></head></__body>
<!-- pageAttribute: NotSearchable -->
<__iframe src="http://www.census.gov/popclock/embed.php?component=counter&popclk=727707" frameborder="0" width="389" height="930" allowtransparency="true" sandbox="allow-same-origin allow-scripts">
</__iframe><__body>
</__html>