For information, i've seen a bug with the last version of Milonic DHTML menu :
sub menu level2, under Firedox are bad displayed when you scroll the Firebox right scrollbar to bottom.
Change the fixMozillaZindex to false. I'm not sure why it's a problem, maybe something to do with the flash objects. Of course I have no way of testing it on my desktop with the flash so I don't know what happens on the web with the flash running and that change.