see example at:
http://web-east.east.sun.com/www/tests/javaws/certtests/1.5/applets.html
2 of the applets here fail with bad certificate error. Dismissing this dialog exits the vm.
basic: Main.systemExit(-1) called
java.lang.Exception: Informal: System.exit(-1) called
        at com.sun.javaws.Main.systemExit(Main.java:1099)
        at com.sun.javaws.security.AppPolicy.grantUnrestrictedAccess(AppPolicy.java:233)
        at com.sun.javaws.LaunchDownload.checkSignedResourcesHelper(LaunchDownload.java:1295)
        at com.sun.javaws.LaunchDownload.checkSignedResources(LaunchDownload.java:1132)
        at sun.plugin2.applet.JNLP2Manager.prepareLaunchFile(JNLP2Manager.java:960)
        at sun.plugin2.applet.JNLP2Manager.loadJarFiles(JNLP2Manager.java:354)
        at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1096)
        at java.lang.Thread.run(Thread.java:619)