j2re-1_4_2_05-linux-i586-rpm.bin is not a RPM and cannot be uninstalled with RPM as you probably not installed it with RPM also.
Removing j2re1.4.2_05 is pretty easy, just delete the folder j2re1.4.2_05 and if you want to reinstall it again you better download the newest version.
Download Linux self-extracting file (jre-1_5_0-linux-i586.bin, 15.75 MB)
(and save it in the root folder)
Login as root
Open the console (Terminal
in System Tools)
chmod a+x jre-1_5_0-linux-i586.bin
(The file manager icon on your desktop)
Copy the whole folder jre-1_5_0
Go to the folder [B]/usr/lib/jre-1_5_0/plugin/i386/ns7
Click with the right mouse button on the file libjavaplugin_oji.so
and select Make Link
Copy the link to your browser plugin folder and rename it to libjavaplugin_oji.so
Logout as root
and login with your user account open your browser and test your Java plugin.
With kind regards,
P.S. I hope this is helpful for you if any question I'm willing to help