Try adding allowfullscreen=”true” at the end
for e.g.
[youtube https://www.youtube.com/watch?v=Ipn5K_M3Ywg&w=640&h=480 allowFullScreen="true"]
This is how i fixed on my blog and it worked out.
Check the video embedded at following link:
http://ztwocents.wordpress.com/etabs2013/
Hope it work for you!!
