Repost, this time without tags that don't work (sorry!):
You can apply a workaround to install the new JRE which is meant for Karmic, in Hardy, Intrepid and Jaunty.
This workaround is for 32-bit Ubuntu only! You have to adapt it for a 64 bit system.
1. Manually download these three files from Multiverse:
2. Put these files in your home folder, don't leave them on the desktop.
3. Applications - Accessories - Terminal
Execute the following terminal commands (use copy/paste to place them in the terminal):
sudo dpkg -i sun-java6-bin_6-15-1_i386.deb sun-java6-jre_6-15-1_all.deb
Press Enter. Your password will remain invisible, not even dots, this is normal.
sudo dpkg -i sun-java6-plugin_6-15-1_i386.deb
4. Ready. :)
Bad that we need a workaround... We shouldn't need one. The package maintainer isn't active enough. :(