Posted by gouessej on Oct 13, 2010; 9:09am
URL: https://forum.jogamp.org/jogl-1-1-1-vs-2-0-jnlp-applet-tp1686929p1693166.html

He gives the solution:
http://forum.processing.org/topic/is-jre-6-update-21-working-with-processing-applet

It does not come from JOGL but from changes in the way Java Web Start loads unsigned JARs.