You linked the wrong file:
Do:
ln -s /usr/bin/j2re1.4.2_05/plugin/i386/
ns610-gcc32/libjavaplugin_oji.so in the plugins directory of Firefox.
Sample from my system:
/usr/lib/mozilla-firefox/plugins$ ls -l
lrwxrwxrwx 1 root root **** libjavaplugin_oji.so -> /usr/share/java.current/plugin/i386/ns610-gcc32/libjavaplugin_oji.so
(java.current here is another symlink to the java folder for easy updating)
I do agree on the not so userfriendly part of this, but noobs should wait for Linspire and Xandros to evolve. I see to many issues a non-techy will never be able to solve. Ever tried to get lm-sensors working?