that's wrong. it's recommended you don't make a copy of the plugin in your mozilla plugins directory.
basically, to allow all users access to the java plugin follow these commands in the shell terminal. make sure to use your correct paths
<enter root password>
2. ln -s /path/to/real/java/plugin /usr/local/mozilla/plugins/file_name_of_java_plugin
again, use your correct paths to the java plugin and your mozilla plugins path. also make sure if you're version of mozilla is 1.4 or greater, to use the java plugin in ns610-gcc32. if the version is less than 1.4, then use the java plugin in ns610. also make sure that the desktop icon and/or command you use to launch mozilla is the correct one. if you've installed mozilla from an install provided by mozilla.org, the command to launch mozilla will most likely be "/usr/local/mozilla/mozilla". your desktop icon should launch that command also. usually mozilla provided by your distro will be in /usr/lib/mozilla-XX.XX where XX.XX is a version number. if this is the case then sub the mozilla plugins path in command #2 to, /usr/lib/mozilla-XX.XX/plugins/file_name_of_java_plugin
hope you get this sorted.