you also get "Accordian is not defined" in ie, probably why your script doesn't work in ff. check the spelling and that you're 100% on the script being imported, not delay-loaded or some nonsense like that. Additionally, be sure that your flash control is windowless, as this can sometimes lead to the object always staying on top of everything else even if the control has a lower z-index or is a child of an object with a lower z-index.
"Want me to precludify him, like some kind of dispatcherator?... Can do!" -Bender