Windows Live Writer 2011 embed YouTube video sends a black image to my site instead

I'm developing a blog app, and using windows live writer 2011 to embed a YouTube video is pretty straight forward, but I've encounter a strange issue. Here is what I did,

1. I copy a link from the YouTube site, for example, http://www.youtube.com/watch?v=3Kk-yZ7VpeA
2. From WLW I insert video From the web and paste the link in it
3. WLW shows the video without any problems
4. I view Source in WLW, it gives the following html <div style="padding-bottom: 0px; margin: 0px; padding-left: 0px; padding-right: 0px; display: inline; float: none; padding-top: 0px" id="scid:5737277B-5D6D-4f48-ABFC-DD9C333F4C5D:bb7a51da-b141-42e1-9e93-72967dd2f73d" cl开发者_JS百科ass="wlWriterEditableSmartContent"><embed src="http://www.youtube.com/v/3Kk-yZ7VpeA?hd=1" type="application/x-shockwave-flash" wmode="transparent" width="448" height="252"></embed></div>

All these are working fine with preview and everything, but when I publish it, it shows up a black squaure of image instead of the video on my site. Moreover, the html WLW sent to the server is the following: <div style="padding-bottom:0px;margin:0px;padding-left:0px;padding-right:0px;display:inline;float:none;padding-top:0px;" id="scid:5737277B-5D6D-4f48-ABFC-DD9C333F4C5D:bb7a51da-b141-42e1-9e93-72967dd2f73d" class="wlWriterEditableSmartContent"><div id="7bd0cee8-cce8-4b10-8833-6e30cefafd64" style="margin:0px;padding:0px;display:inline;"><div><a href="http://www.youtube.com/watch?v=3Kk-yZ7VpeA" target="_new"><img src="http://127.0.0.1:10000/devstoreaccount1/ray/blog/image/2011/05/videob8758375cccf.jpg" style="border-style:none;" alt="" /></a></div></div></div>

Note the "embed" tag was no longer there and an "img" was instead created. I don't really know why WLW sent what it sent and how to fix this issue, could someone help point out please.

Thank you so much!

I got it figured out. I added

<supportsEmbeds>Yes</supportsEmbeds>

to wlwmanifest.xml file. Without this line, WLW shows the blog capabilities for "Embeds" as "Unknown" and it messes with the embed tag.