The customer observed the behavior difference between Java 5.0 and Java 6.0 in the below scenario. This behavior is seen with JDK7 as well.

In Java 1.5.0 When a child window is closed, the focus returns to the parent window. While in Java 6.0 when a child window is closed the focus goes to the shell window that started the java process. If the window that started the java process is iconifyed, then there is no focus.

The following table shows where the problem is reproducible.

JDK ToolKit Issue reproduced
5.0 MToolKit No
5.0 XToolKit No
6 MToolKit No
6 XToolKit Yes
7 XToolKit Yes

The test case is attached to the bug report.