I accidentally stumbled upon a small inconvenience yet again as a web designer; as you can see my current design uses a flash movie under <div> elements. Normally the flash content will be on top regardless of the stacking order in your code or via z-index. It turns out setting your flash movie's window mode ("wmode") to transparent will fix the issue (only in a perfect world). Sadly this doesn't work on firefox on linux platforms, based on my reading the wmode attribute is still not supported on linux/firefox.

I've read somewhere that google was able to pull this off by inserting an <iframe> right under your <div> width the same dimensions and using a little javascript hack. Long story short the iframe must have a display property set to none at first, then set back to block once the page has loaded. I implemented this on my current layout and it seems to work. To test this you can visit browsercam.com, they offer a free trial to take screenshots of websites under different platforms/borwsers.