Installing Firefox4 beta with working plugins

[Jim Byrnes]

I wanted to try out the Firefox4 beta.  I followed the instructions for 
installing it found here:

 
http://www.liberiangeek.net/2010/12/install-firefox-4-beta-ubuntu-10-10-maverick-meerkat/

It runs but about:plugins shows that no plugins are installed.

How do I activate the plugins? In particular I was trying to get the 
java plugin to work.  I have installed the Sun jre and plugin from the 
partners repository.

I am testing this on Meekrat running in virtualbox on Ubuntu 10.04 AMD64.

Thanks,  Jim