Well basically Bill Gates has been slapped in the face by people he stolen code from.
Thus Internet Explorer is no longer capable of loading ActiveX media directly from the markup: it must be printed in the document dynamically (from any kind of script).

You can find all sorts of fixes, but a very good practice is to use the acclaimed swfObject script, that does all the dispatching stuff and loads the content in place.

If you need to find info on this subject, google "EOLAS FIX" and "SWFOBJECT".

Ciao