We have JDK-8164462 closed as a duplicate to JDK-8161910; that last one is marked as fixed in b140, but javax/swing/JInternalFrame/8146321/JInternalFrameIconTest.java still fails on Unity (I use Ubuntu 16.10 this time, on the same dual screen hardware) with the similar symptoms. Namely, the second frame, painted with Metal LaF, is empty and background-gray. All is OK with Nimbus LaF and with the first show with Metal.

RULE "javax/swing/JInternalFrame/8146321/JInternalFrameIconTest.java" Exception java.lang.RuntimeException: Error Log: [javax.swing.plaf.metal.MetalLookAndFeel] : ERROR: icon and imageIcon not same.