Problem Statement
  =================
  Web application that utilizes Java applets. All applets are signed. A very
  small percentage of users receive an error message when an applet is
  launched saying that the applet uses both signed and unsigned content and
  should not be trusted. Frequently, the browser also hangs when this
  message is displayed. Closing the browser or refreshing the page often
  makes the problem go away. This message is spurious as all applets are
  signed and the majority of users have no problem using the application even
  though they are hitting the same webpages/applets on numerous versions of
  Java including Java6 update 19 through update 24.
  Refer to Sun Bug 6805618
  
  Issue Clarification
  ===================
  1. Cannot deterministically know when the error will happen.
  It is spurious.
  
  2. No testcase
  
  3. It happens on user 6u19 -> 6u24
  
  4. tried altering java applet settings to use extremely small memory sizes
  in order to reproduce the problem but have so far been unsuccessful.
  
  system configuration
  ====================
  From 6u19 to 6u24.
  Mainly on Win XP