Video works until I edit post- then video is lost

– I embed a video into a post and it works.
– it continues to work unitl I edit the post
– once I edit the post, I loose the video
– a box with a red x appears in the top left corner where the video resided
– this happens on pages also

Any ideas on how I can fix this. Thanks

https://www.sitesmarty.com (see recent videos – January 1, 2008)