Correctly Embedding Flash/Youtube Videos
Internet Explorer is fucked anyway, so if you don’t definitely need compatibility to IE you better go with the internet standard all other browsers use.
To embed a youtube video for example, just use the object-tag, and use it the right way:
YouTubes embed code itself is not really standard. Its object tag does neither use the type-attribute nor the data attribute. Both are to be used if you want to go with the standard.
And even worse, the embed-tag is used, inside the object-tag. Just leave it. (Although it’s (re-)introduced in HTML5, it has a totally different meaning there.)
For your reference: