Also make sure that OpenJDK (when sun-java6-jre is installed) is not set as the default java-alternative and please make sure the sun-java6-plugin is the default mozilla/firefox plugin and not the icedtea-gcjwebplugin (when sun-java6-plugin is installed).
Also make sure that OpenJDK (when sun-java6-jre is installed) is not set as the default java-alternative and please make sure the sun-java6-plugin is the default mozilla/firefox plugin and not the icedtea- gcjwebplugin (when sun-java6-plugin is installed).