Comment 2 for bug 511443

I'm having the same problem with kubuntu karmic koala. I've installed sun-java6-* packages, including sun-java6-plugin, and created a symlink of libjavaplugin_oji.so in the mozilla's plugins directory:
/usr/lib/mozilla/plugins
and firefox's:
/usr/lib/firefox/plugins
but nothing works. If I try to open an applet with firefox it says, "missing plugin". I opened "about:plugins" and I didn't found java plugin. Finally i tried to open an applet with google-chrome and it worked. Mi system:
Dist: Ubuntu Karmic Koala
Kernel: 2.6.31-17-generic
Firefox / Namoroka version: 3.6.1pre