Are you sure you downloaded the LW 5 version & not the classic version?

I am aware iTool has an option for Resetting Launch Services which may or may not help your scenario.

Go to your Go menu & choose Utilities folder. Open the Java folder. Open Java prefs, see if Java 1.6 (Java SE6) is listed. Setting up Java for Leopard (see 2nd image)

If Java SE 6 is not listed then your computer is not compatible with Java 1.6/LW 5. In that case see http://www.gnutellaforums.com/mac-os...ck-lw-4-a.html