Z-indexes on IE 6 works almost like on any other browser, but if something does not work for you, please do not forget to check (or even double check) the paramter for transparent background of the flash. Not only the z-index, and absolute positioning is needed, just add this line of code in your object tag:
<param name="wmode" value="transparent" />
Why flash does not work correctly with Flash ExternalInterface see here:
How to write object tag to make your IE browser work I’ve written here:
- HTML object and embed tags/ – (part 1)
- object & embed tags revealed – (part 2)