Comment 2 for bug 217940

/etc/alternatives/xulrunner-addons-flashplugin had not been set to the swfdec mozilla plugin after deinstall of flashplayer-nonfree and install of swfdec (after deinstall of flashplayer). update-alternatives fixed this.
(not including other commands (and dpkg -l \*swfdec\* is more efficient, right ;))).

it works ok with this link fixed. i have no idea, why this did not happen. i guess the bug should not be closed, until it is clear, why update-alternatives was not run.