Hey Marcello,
I had the same problem with a debian system.
You are using an outdated version of flash, you can still watch flash by clicking on 'allow' but you should really upgrade.
The main issue here is that, flash player is not licenced by default and not packaged. The software that installs it on your system is called flashplugin-nonfree, but for whatever reason package maintainers decided not to bump its version number to force everyone to upgrade.
You need to reinstall flashplugin-nonfree or flashplugin-installer however it is called in ubuntu, by running "aptitude reinstall flashplugin-nonfree" which you did. However, End-of-life of Ubuntu 12.10 was reached on May 16 this year --
http://fridge.ubuntu.com/2014/05/17/ubuntu-12-10-quantal-quetzal-end-of-life-reached-on-may-16-2014/So security repository is no longer active.
This is the point where I, as all other people in the list would recommend you to upgrade to the latest Ubuntu LTS release, however if you want to just fix this problem, keep reading.
Open terminal, type
$sudo gedit /etc/apt/sources.list
enter a password if asked
Then run aptitude updated && aptitude reinstall flashplugin-installer.
You should be good to go.
Alex.