Uninstall your Java and reboot. Then download the JRE offline installer of the newest Java version (1.5.0_07) from here:
http://java.sun.com/j2se/1.5.0/download.jsp
Install it and reboot. Then start LW.
If that doesn't solve it, uninstall both Java and LW, reboot and install Java again, reboot and then install LW.