I'm using Dreamweaver CS3 and the property inspector in this version doesn't seem to have anywhere to set these parameters for the Flash movie.
Having looked at the code there seems to be only 3 places that WMODE could be inserted - so I stuffed it in all three places and behold the menues are now visible in Firefox, Maxthon, Chrome, Sarafi and Opera.
The menus are still being obscured in IE9 ...
I guess 5 out of 6 is reasonable - just a pity the duff one is IE as I've heard that rather a lot of people use this !!