I am running a Java applet compiled in 1.5 and am experiencing odd behavior when running it on computers running 1.6.0_07 and 1.6.0_16. On the *_07 version, the applet initializes and loads in the browser perfectly fine. However, computers with the *_16 are not loading at all. Even more strange, there is nothing in the Java Console to indicate any problems will loading the applet in the browser. If I run the applet from as a standalone app on said machines, it loads up just fine. The compatibility mode in the JNLP is set to 1.5+. Firefox reports no errors attempting to load the applet. Even with full tracing and logging set to all, nothing is reported in the console window.

Quick facts:

• The JAR is signed
• Compiled in 1.5
• Works flawlessly in browsers (FF & IE) running *_07
• Does not work in browsers (FF & IE) running *_16
• Works running as stand alone app in *_16
• JNLP set to 1.5+
• Clients are mixed *_07, *_16, and other version of 1.6

Things I have tried:

• Forcing the JVM to use version 1.6.0_07. This requires the user to download *_07. In my situation this is not an option, unfortunately.
• Ran the app on *_16 as a standalone app. This works fine, but this needs to run as an applet.

Ideas?