The java plugin question
open a command line a cnage into your mozilla plugin directory
cd /usr/lib/mozilla-1.6/plugins (or whatever/wherever it is)
ln -s /usr/java/j2re1.4.2_03/jre/plugin/i386/ns610-gcc32/libjavaplugin.so (this path may be different as I use the sdk)
Point is - you want to cd into your mozilla plugins directory and make a link, ln -s, to the file libjavaplugin.so wherever it may be on your system
PS. It is an applet in your browser you're trying to run, yeah?