Problems with embedded video

I am trying to post codes for a wmv file – embedded.
1. I can only post the codes ones – and they do not reappear in the html box
2. I cannot write any text afterwards – somehow it is deleted or removed when trying to save and publish the post.

Is there anyway I can work without the “text box” feature, so I can write and edit codes in the posting, and what am I doing wrong when trying to write plain text afterwards…?

Does this make sense?