Comment 218 for bug 173890

> My flashplugin-nonfree is b0rked on gutsy/amd64 by latest update (today 2008-02-07), exactly as
> reported by Diego Gaustein (immediately above).

The fix for this is as follows:

$ sudo rm -f
/var/cache/flashplugin-nonfree/install_flash_player_9_linux.tar.gz

I imagine this is being worked on to fix, as was noted earlier today.
If you encounter these problems, please enter this command, and try again.

In general, don't trust people who tell you to "sudo rm" anything :)
But this is an exception, as it's just a file that apt downloads for
you. The problem is that it's using your local copy, which is broken.
If you delete your local copy, apt will get the new (and working) one,
and everything should go fine. If not, post the problem.