When you export the swf there should be an HTML container in the same destination folder. If you view that HTML file in a browser do you get what you expect?
If you are moving the swf to another HTML page make sure the embed code parameters match. So in the boilerplate HTML ID creates the body tag and the embed parameters both have bgcolor as #999999:
When you move the swf make sure the div tag that encloses the swf has the same bcolor style color as the embed code's bgcolor
Rob gave you the answer but I'll ask a question. Why are you using SWF?
It's not viewable at all on mobile devices and less and less people have
it installed on desktops.
I've looked into things a little more closely since I'm not that up on using
animation. I take your point though, will move on. Thanks