Regression: YES (from b72)
Version:
java version "1.6.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-beta2-b72)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b72, mixed mode, sharing)

Bundles tested:
jdk-6-rc-bin-b71-linux-i586-09_feb_2006.bin
jdk-6-beta2-bin-b72-linux-i586-16_feb_2006.bin
jdk-6-beta2-bin-b86-linux-i586-02_jun_2006.bin

Platform: Linux ptakopysk.czech.sun.com 2.6.9-5.EL #1 Wed Jan 5 19:22:18 EST 2005 i686 athlon i386 GNU/Linux

Description:
Java plugin does not work - it displays blank space on a webpage and dumps plugin_stack.trace to current working directory.
Content of plugin_stack.trace:
java.lang.NoClassDefFoundError: Could not initialize class com.sun.deploy.config.Config
        at sun.plugin.AppletViewer.initEnvironment(AppletViewer.java:263)
        at sun.plugin.navig.motif.Plugin.doit(Plugin.java:141)
        at sun.plugin.navig.motif.Plugin.start(Plugin.java:104)

Browser: Firefox

Reproduce Step(s):
1) install jdk-6-beta2-bin-b72-linux-i586-16_feb_2006.bin or later to the home directory
2) cd ~/.mozilla/plugins
3) ln -s ~/jdk1.6.0/jre/plugin/i386/ns7/libjavaplugin_oji.so
4) Run mozilla browser and check the correct installation of the plugin by navigating to "about:plugins" page.
5) Navigate to a page containing a java plugin (http://java.sun.com/products/plugin/reference/codesamples/index.html)
6) Check the dumped file plugin_stack.trace in the current working directory