WordPress Editor problem

Hello ,

I have faced a problem in wordpress editor . Here is the problem :

If you create a post and paste a youtube video in the post, the video will work if you save it only after pasting in the html format, but as soon as you switch to the visual view on the dasboard, the video disappears from the post. If you load a video in to the Visual view and save, the video disappears.

You can try using this video :

<iframe title="YouTube video player" width="640" height="390" src="https://www.youtube.com/embed/kI3Yq1REiuo?rel=0" frameborder="0" allowfullscreen></iframe>

I think its a wordpress editor problem , can anyone provide me the solution of this .

Thanks in advance