Making small changes to an existing website presents its own unique challenges, as ideally you’d like to change only what is absolutely necessary. When the previous builders have used their own CMS, and Javascript which was automatically generated by a Macromedia/Adobe product (oh, yes), not to mention a little flash thrown in for good measure, it can amount to basically reading pages of code to figure out what’s going on before you do anything.
In this case, when all was said and done, we had a Javascript dropdown menu which dropped over a little design element that had been done in flash. Problem was, the Flash always wanted to be overtop of the menu. Setting unreasonably high z-index properties for the menu elements did not seem to help.
Solution
This may or may not help others, but in this case the secret sauce was to add <param name="wmode" value="transparent"> among the other params, and also to add wmode="transparent" as an attribute in the embed tag for the Flash object.
I think a better solution would be to not use flash in this particular place — but I’m not really interested in fighting that battle this time.
I've noticed that happening in a lot of places – javascript menus dropping down under flash content. Does it happen across all browsers, or is it just a firefox thing?
I believe it can happen in IE as well, though I don't have a convenient way to test that theory.