Comment 16 for bug 299146

Even though the 64bit plugin hasn't been marked as 'final' it is the same version as the 32bit version of flash. Debian's own package (version 2.8 in Squeeze and Sid) downloads the 64bit plugin with it's version of flashplugin-nonfree. It even works on Ubuntu's. So in this case, Ubuntu just hasn't synchronized the package with Debian.

I had a hell of a time on my Fedora 11 install to get Flash working with sound. Come to find out it's an issue between pulse and Flash (Surprise surprise!) and the core of the issue is that libflashsupport does not work under 64bit. It has in fact ceased development because the newer version of Flash 10 no longer needs it. But this means that unless you have 32bit pulse running with 32bit flash, then you won't get sound. 64bit really is the way to go. The less dependencies on 32bit libraries on a 64bit system, the better.

Firefox can really run at 64bit now since Java and Flash both have 64bit plugins. So just update the package already. Hell, just sync with Debian's package.