Customer has created some custom awt components in their applet that worked well under 6u11, but now won't display under 6u12. In the release notes for 6u12, we see that there has been a change relating to the mixing of lightweight and heavyweight components. Which is mentioned on the following link:

http://java.sun.com/javase/6/webnotes/6u12.html

The customer has provided screen shots of their production app that uses these components as well as a standalone test case. Please see the attachment section of this bug for information on how to access that data.