thing is you're using HTML Snippets. HTML Snippets add a new page to which the code is added and this page gets iFramed into the original page you added the Snippet to. HTML Snippet's background is white. What you could try to do is copy and paste this entire code into the HTML Snippet which makes the background of the HTML Snippet page be black
Another thing is that thehttp://web.me.com/andrewwonder/Site_4/iframereel.html
page has only the content-backgorund being black and you should set the browser background (Inspector=>Page tab=>Layout) to black too.
I don't know whether these two things solve your problem but at least they should improve a bit.