Hangman demo (http://tachyon.eng/java.sun.com/JDK-prebeta1/applets/Hangman/index.html) worked correctly in Prebeta 1, fails in prebeta1a and later with the following errors:

Solaris:
java.lang.NullPointerException exception when loading: classes.Hangman
load: class classes.Hangman not found
java.lang.ClassNotFoundException classes.Hangman
at java.lang.Throwable.<init>(Throwable.java)
at java.lang.Exception.<init>(Exception.java)
at java.lang.ClassNotFoundException.<init>(ClassNotFoundException.java)
at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:118)
at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:101)
at sun.applet.AppletPanel.run(AppletPanel.java:219)
at java.lang.Thread.run(Thread.java)

Win32:
File format exception when loading: classes.Hangman
status: load: class classes.Hangman not found
load: class classes.Hangman not found
java.lang.ClassNotFoundException: classes.Hangman
        at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:125)
        at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:101)
        at sun.applet.AppletPanel.run(AppletPanel.java:232)
        at java.lang.Thread.run(Thread.java:286)
status: init: applet not loaded
status: start: applet not initialized
status: stop: applet not started
status: destroy: applet not stopped
status: dispose: applet not destroyed

Same problem with WordMatch applet:

http://tachyon.eng/java.sun.com/JDK-prebeta1/applets/WordMatch/index.html