1st I'd suggest you reboot whilst holding down the SHIFT key until you see the Safe Booting message & after started, go to utilities folder, open Disk Utility & repair permissions. Then reboot. See if any change. Do you have any 3rd party utilities such as norton or TechTool Pro? I'd recommend re-installation of Java using the "Offline" standalone installer if that doesn't work. Java 1.4.2 for Tiger (click on link) (Sorry I'm not 100% sure that's the most recent Java version but may as well try.)

If you get the "null" message in the Apple installer when a OS X thinks a more recent version is installed. Double-click the harddrive icon, open the Library, open the Receipts folder, then find the file: java???.pkg, delete it and try again. Receipts folder sample image

BTW are you aware that you can use Java 1.5 for LW which will make it perform better. http://www.gnutellaforums.com/showth...230#post176230