I hear folks are having trouble imbedding YouTube Videos. I have had trouble too. I’ve been doing the end run around this technical difficulty by going into edit mode of previous YouTube posts and copying the html YouTube code. I then replace the older YouTube link with the new one. I use the longer old style YouTube link (available as a YouTube Share option).
Below is the the HTLML code you can use:
[youtube]cut+and paste+the+long+youtube+link+here[/youtube]