Im writting this because none of the howtos Ive seen have worked for this they all were wrong in one way or another. Now I like to use "BUMPS" - Basic Ubuntu Multimedia Preparation Script which is freely available to download from this thread

Anyways just install the sun java and the sun java plugin are not enough. You then must make a symbolic link of the java plugin to your firefox install. So if you enter the following command into a terminal you then will have a java capable browser.

Code:
sudo ln -fs /usr/lib/jvm/java-1.5.0-sun-1.5.0.06/jre/plugin/i386/ns7/libjavaplugin_oji.so /usr/lib/firefox/plugins/libjavaplugin_oji.so
Note this will only work if your java and firefox are installed in the same location as mine thats why I would recommend using BUMPS to install the upgraded firefox, sun java rte package, and the sun java plugin.

Also I would like to add bumps is a pretty sweet program that will have your system up and running for media wise in just a few minutes.

Please make sure you thank Iandefor for all his hard work and for sharing his sweet little app =D>