Change from OpenJDK to Sun JDK
OpenJDK is an effort to put java open source (GPL "enabled"), but the JVM is not yet robust Sun JVM.
So if you want to change follow these steps:
Install Sun Java Runtime Environment
# sudo apt-get install sun-java6-bin sun-java6-fonts sun-java6-jre sun-java6-plugin
Change from OpenJRE to Sun JRE
# cd /etc/alternatives
Creating backup
# sudo mv java java_old # sudo mv mozilla-javaplugin.so mozilla-javaplugin.so.old
Creating Symbolic links
# sudo ln -s /usr/lib/jvm/java-6-sun/jre/bin/java java # sudo ln -s /usr/lib/jvm/java-6-sun/jre/lib/i386/libnpjp2.so mozilla-javaplugin.so
Restart your firefox and test accessing http://java.com/en/download/help/testvm.xml