Problems with mplayerplugin

[Bruno Wolff III]

I just noticed today that firefox is not doing things nice with plugins
and filed a couple of bugs and until things are fixed have removed
the plugin wrapper and a couple of flash players.

It won't let you set the action for video/x-flv to save file.

Firefox re-enables disabled plugins on startup. This one's really cute, as
you need to be root to disable and re-enable plugins normally.

I don't know whether or not this is related to what you are seeing or not.
But it is relatively new behavior.