In the test javax/swing/JInternalFrame/Test6325652.java ,
Control + F9 is used to iconify the JInternalFrame which works fine (need to add robot.setAutoDelay(50) after creating robot object)
but using Control +F6 and then Control + F5 does not restore the iconified frame.

The test works fine using the Metal and Nimbus LookAndFeel.(need to add robot.setAutoDelay(50) after creating the robot object)