My first advice would be to uninstall both Java versions (1.6 is the beta and 1.3 pretty old -both might not be suitable for your computer size.
Try to download the JRE offline installer of the newest Java version usable for your system:
http://java.sun.com/j2se/1.5.0/download.jsp
Uninstall LW and Kaaza, after removing the Java, then reinstall the Java using the offline installer, reboot, then reinstall either LW or Kaaza (not both).
See if that does the trick.......