Fair enough When strictly using the object tag, IE can have difficulty streaming, so one solution is a container movie, but that's starting to get a bit ahead.
Have you tried to access the swf directly from your browser (like http://www.domain.com/coolmovie.swf)? If that works, then all you need to add is something like this:
That's pretty much the bare minimum, if I remember correctly. Anyone know if you can use styles rather than attributes for setting the sizes on object tags? (and whether browsers will pay attention?)
Check out Gordaen's Knowledge, the blog, and the MR2 page.