Ubuntu 10.04 LTS and Java

I couple of weeks ago following a 10.04 LTS update the Java(sun-java6-plugin) in Firefox (and Google Chrome)stopped working. I reinstalled 10.04 and the same thing happened following a substantial update. Is there a feature that should not be updated?

I have installed OpenJDK with synaptic and checked with the terminal - sudo apt-get install openjdk-6-jre - but it still does not work.

Thanks

Alan