Hi there,
Yes I have the full screen browser wet to letterbox scale as well as I have installed it after. Here is what my index.html looks like with the surrounding code.
<!-- WinJS references -->
<script src="//Microsoft.WinJS.1.0/js/base.js"></script>
<script src="//Microsoft.WinJS.1.0/js/ui.js"></script>
<!-- Microsoft Advertising required references -->
<script src="/MSAdvertisingJS/ads/ad.js"></script>
</head>
<body>
<div id="fb-root"></div>
<!-- The canvas must be inside a div called c2canvasdiv -->
<div id="MyAd" style="position: absolute; top: 53px; left: 0px; width: 250px; height: 250px; z-index: 1"
data-win-control="MicrosoftNSJS.Advertising.AdControl"
data-win-options="{applicationId: 'testclient', adUnitId: 'ADPT33'}">
</div>
<div id="c2canvasdiv">
<!-- The canvas the project will render to. If you change its ID, don't forget to change the
ID the runtime looks for in the jQuery events above (ready() and cr_sizeCanvas()). -->
<canvas id="c2canvas" width="720" height="480" oncontextmenu="return false;" onselectstart="return false;">
The browser appears to have HTML5 disabled. Try checking the compatibility settings.
</canvas>
</div>
<script src="jquery-1.7.1.min.js"></script>