The first thing to check is that your Flash is set to windowless mode by setting WMODE to "opaque" or "transparent" - see
http://kb2.adobe.com/cps/155/tn_15523.html. If you've got that set OK, then start playing with your z-indexes to get everything in the right order (and note that there is a bug in IE6 and IE7 where you have to specify a z-index for all an element's positioned parents, see e.g.
http://webdemar.com/webdesign/super...ndex-bug/, so be sure to test in IE7!).