/usr/lib/firefox/plugins/flashplugin-alternative.so is a symbolic link to /etc/alternatives/firefox-flashplugin. So an alternative solution is
sudo ln -s /etc/alternatives/firefox-flashplugin /usr/lib/firefox-3.0b4/plugins/flashplugin-alternative.so
But this is no fix, just another hack in the wall
/usr/lib/ firefox/ plugins/ flashplugin- alternative. so is a symbolic link to /etc/alternativ es/firefox- flashplugin. So an alternative solution is
sudo ln -s /etc/alternativ es/firefox- flashplugin /usr/lib/ firefox- 3.0b4/plugins/ flashplugin- alternative. so
But this is no fix, just another hack in the wall