Mac OS 10.5 Leopard Startup Error 'Failed to validate certificate' error

A 'Failed to validate certificate' error has shown up on 10.5 systems upgraded from 10.4, particularly on the Core 2 Duo systems that recently got Java 1.6 into Leopard via Software Update.  

To resolve these startup errors, using Finder go into Java Preferences (open Finder, select Applications, the Utilities folder, the Java folder, then open Java Preferences.app) and look on the first tab under the Java Application Runtime Settings. 

The Java versions loaded will all be listed to the left, and what we have found is that J2SE 1.4.2, the oldest version, is listed first.  Drag and drop the higher Java versions so they display in descending order, starting with Java/J2SE 6 64 bit (if present, otherwise just Java/J2SE 6), then J2SE 6, the 5.0, then 1.4.2.  Once arranged, click Save and ROES should open fine from the shortcut or lab web link.