[CentOS] Installing Java on X86_64 CentOS 4.1

I have some problems installing java support to my browser (firefox). 
This support I installed with no problem when running the 32 bit version 
on the same machine, but now I can't find the plugin.
I running on S754 - AMD XP3000

this is the file i download:
jre-1_5_0_04-linux-amd64.bin

And I am following the installation instructions from this link:
http://java.com/en/download/help/5000010500.xml

Everything seems to install perfectly, but the libjavaplugin_oji.so is 
not included, I can't find.
Maybe there is an other file to link up to? If someone has the answer, 
please!

kai