youtube problem

hello. there seems to be a problem with my blog these days.
before I had no problem embedding videos from youtube but now they seem not to work, where I only see a link when I paste it.
this happens when I have multiple images in my topic.
I tried post a new topic with no pictures and only youtube video link and it worked.

any suggestions?

here is a link of one blog that has the problem
http://pclink4host.com/?p=445