No Really...

bryan@homer:~$ dpkg -p flashplugin-nonfree
Package: flashplugin-nonfree
Priority: optional
Section: contrib/web
Installed-Size: 164
Maintainer: Ubuntu MOTU Developers
Architecture: i386
Version: 10.0.1.218+10.0.0.525ubuntu1~hardy1+really9.0.124.0ubuntu2

It's a really long thread of explanation..
https://bugs.launchpad.net/ubuntu/+source/flashplugin-nonfree/+bug/235135

Basically, flash10 and pulseaudio actually get along with Flash10. Firefox on the other hand does not :P. They reverted it out of backports due to this new bug.