i am also having the same problem, i posted a large-scale video onto my nieces site..
http://jennifer-forbing.last-memories.com/i used the embed-code..
<object width="960" height="745"><param name="movie" value="http://www.youtube.com/v/kK3fOoxy1wE&hl=en_US&fs=1?rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/kK3fOoxy1wE&hl=en_US&fs=1?rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="960" height="745"></embed></object>
its too large, but when i go back into edit, it doesnt show the embed-code, to remove it
please help