Can you not have a htaccess point toward an html page with flash embedded within it?

I currently have this line of code on my .htaccess file:

ErrorDocument 404 /errors/404.html


It points to http://www.justapixel.com/errors/404.html

When I navigate to the page, it loads fine. But when I type in something like http://www.justapixel.com/nothere.html (where that page does not exhist) it loads the page, but not the flash that is embedded within the page.

How can I correct this?