I embedded a youTube video into one of our pages, and when going to edit the said page the video would sit above the edit modal making it difficult to edit the page.
To fix this you simply add ?wmode=opaque directly after the url in the embedded code you get from youTube
An example of this:
<iframe width="420" height="315" src="http://www.youtube.com/embed/vcSDAAS_Zbw?wmode=opaque" frameborder="0" allowfullscreen></iframe>
I’ve tested this in Chrome, Firefox, Opera, IE9, IE8, IE7 and its works perfectly. (The youTube video above is from the Pagelime channel)