Help – My video html keeps getting stripped away

When I insert video tags or html to a site from a hosting site like vimeo the page displays properly for a while and then for no reason I understand, suddenly the code is gone from the editor.

this was the page that got stripped. the Video was right below the title. http://realfoodforlife.com/welcome/

this next page had You Tube coding which did NOT get stripped.
http://realfoodforlife.com/heart-attack-grill/

Why or how is this happening. How can i stop wordpress from doing this?