Just a quick note, but it looks like a bug in Firefox 3 (soon to be released) will break some existing Flash content. Specifically, it looks like it breaks onKeyUp events in Flash.
You can find more info, and view the bug here.
Unfortunately, it does not look like they will fix this for the 3.0 release, but may fix it in the first 3.0 update.
UPDATE : Mozilla decided to fix the issue (woot!), and has posted a new build. Make sure to check out the build and test your content.