This tutorial might help?:
http://www.wdvl.com/Multimedia/Windows_Media/index3.html(says it works for IE and Nestscape)
Sounds like an issue I had with embedding sound files:
<bgsound src='Web_Music_40-5.WAV' autostart='true'> // Works for IE
<embed src='Web_Music_40-5.WAV' autostart='true'> // Works for Mozilla
... but something funky was happening if I put both lines in... I couldn't be bothered to use a javscript browser detection cuz nobody has javascript enabled anymore (at least they say they don't)... so its virtually useless, one must design for IE or Mozilla, one or the other... or do it all with serverside scripts (php, asp etc..) that detect the browser before sending output...